http://www.youtube.com/watch?v=by0JhirtO-0&feature=related
http://www.flypmedia.com/issues/23/#5/1
Pax Scientific
http://www.paxscientific.com/
A Fascination with Flow
Scientists, philosophers, and artists have been captivated by fluid flow for hundreds of years. Da Vinci spent the last 10 years of his life painting spiraling whirlpools and Bernoulli was fascinated by the curves he saw in natural flow. With the advent of powerful mathematical tools and the Navier Stokes equations, scientists such as Theodore von Karman, G.K. Batchelor, and Hans J. Lugt carried out comprehensive studies of fluid movement and vortical flow.
PAX Scientific CEO Jay Harman is the first person to isolate the geometries that underlie natural flow and adapt those geometries to technology. As a naturalist with the Australian Department of Fisheries and Wildlife (DFW), he developed a fundamental understanding of the flow geometries of ocean and air currents. He repeatedly encountered the effectiveness of natural flow. From his observations, he asked a simple question: “If fluids always tend to follow a particular path, is there a way to design equipment that takes advantage of this fact?”
The Streamlining Principle
The answer to Harman's question is what we call the Streamlining Principle. This approach translates nature's flow efficiencies into streamlined design geometries. PAX can then employ these geometries to significantly improve the performance, output, and energy usage of a wide range of technology. This conscious emulation of natural solutions, dubbed biomimicry by author Janine Benyus, gives PAX a distinct commercial advantage.
Harman first applied the Streamlining Principle to nautical design, producing the award-winning Goggleboat and WildThing series of watercraft. Built using Harman's streamlining geometries, these boats confirmed many of the underlying theories of the Streamlining Principle. In 1997, PAX Scientific was founded to bring the exceptional efficiencies of natural flow to fluid-handling technology, such as fans, mixers, pumps, turbines, heat exchangers, ducts, propellers, and other applications. To validate the Streamlining Principle, the company entered a research relationship with Cascade Technologies and Stanford University. This research confirmed theories underlying Harman's discoveries and identified substantial improvements in the performance of PAX technology when compared with traditional technology.
WO2005003616
NOZZLE AND VENTURI FOR FLUID FLOW CONTROL
NOZZLE AND VENTURI FOR FLUID FLOW CONTROL
Field of the Invention
The present invention relates to nozzles, diffusers and venturis. It may be applied in any application in which conventional nozzles, diffusers and venturis are used.
Background Art
Nozzles, diffusers and venturis are specific types of ducts used in relation to the flow of fluid. For the purpose of this specification, a nozzle is intended to mean a duct of varying cross-sectional area which is designed so that fluid flow is accelerated by a pressure differentiated between the inlet and the outlet. A diffuser is intended to mean a duct of varying cross-sectional area which is designed so that fluid flow is decelerated by an increase of pressure between the inlet and the outlet. A venturi can be seen as a duct comprising a nozzle section and diffuser section abutted in tandem.
Nozzles are widely used in the field of fluid flow as a means to provide an accelerated stream of fluid and have many applications. Diffusers are used to decelerate fluid flow and again have many applications. Venturis are used to cause a short region of accelerated flow in a duct. It is a well known law of thermodynamics that the accelerated fluid flow is accompanied by a reduced pressure, and that many applications of venturis are directed to utilising the reduced pressure.
While nozzles, diffusers and venturis are widely used, it is also well known that their performance is affected considerably by turbulence and frictional losses.
These factors significantly limit the uses to which such devices can be applied.
Disclosure of the Invention
Accordingly, the invention resides in a flow controller adapted to control a flow of fluid within the controller, the flow controller having a flow path adapted to convey said fluid, wherein the cross-sectional area of the flow path varies along the flow path and wherein in at least a portion of its length the flow controller comprises an active surface capable of influencing the fluid flow through the flow path.
According to a preferred feature of the invention, the active surface is adapted to cause rotational motion of fluid within the fluid pathway about the axis of flow of the fluid.
According to a preferred feature of the invention, the active surface is adapted to cause vortical motion of fluid within the fluid pathway about the axis of flow of the fluid.
According to a preferred feature of the invention, the configuration of the active surface conforms to at least one logarithmic curve conforming to the Golden Section.
According to a preferred feature of the invention the curvature of the active surface is uni-dimensional.
According to a preferred feature of the invention the curvature of the active surface is bi-dimensional.
According to a preferred feature of the invention, the curvature of the active surface varies in accordance with the Golden Section.
According to a preferred feature of the invention, the curvature of the active surface conforms to an equiangular spiral.
According to a preferred feature of the invention the curvature of the active surface is transverse to the central axis of the fluid pathway.
According to a further preferred feature of the invention the curvature of the active surface can be in a direction parallel to the central axis.
According to a further preferred feature of the invention the curvature of the active surface is both transverse to the central axis and is parallel to the direction of the central axis to define a three-dimensional surface conforming substantially or in the greater part to the Golden Section.
According to a further preferred feature of the invention the fluid pathway has a spiral configuration. According to a preferred embodiment the configuration takes the form of a logarithmic helix or a volute or a whorl.
According to a further preferred feature the cross-sectional area of the flow path varies logarithmically substantially or in greater part in conformity to the Golden Section.
According to a further preferred feature, the cross-sectional area of the flow path varies to cause the incremental volume of the flow path to vary logarithmically.
According to a further preferred feature, the incremental volume is caused to vary in conformity with the Golden Ratio.
According to a further preferred feature of the invention the active surface has the configuration conforming to the external configuration of a shell of the phylum Mollusca, class Gastropoda or Cephalopoda. According to particular forms of the invention the active surface conforms to the external configuration of shells selected from the genera Volutidea, Argonauta, Nautilus, Conidea or Turbinidea.
According to a preferred embodiment the active surface has the configuration of the interior of shells of the phylum Mollusca ; classes Gastropoda or Cephalopoda. In particular examples of the embodiment the active surface has the configuration of the interior of shells selected from the genera Volutidea, Conidea, Turbinidea, Argonauta, or Nautilus.
According to a preferred feature of the invention the configuration of the flow controller promotes substantially radially laminar fluid flow.
According to a preferred embodiment, the flow controller comprises a nozzle.
According to a preferred embodiment, the flow controller comprises a diffuser.
According to a preferred embodiment, the flow controller comprises a venturi.
The invention will be more fully understood in the light of the following description of several specific embodiments.
Brief Description of the Drawings
The description is made with reference to the accompanying drawings of which: Figure 1 is a chart of the Golden Section or Fibonacci Progression; Figure 2 is an isometric view of a nozzle according to a first embodiment; Figure 3 is an isometric view of a nozzle according to a second embodiment; Figure 4 is an isometric view of a nozzle according to a third embodiment; Figure 5 is an isometric view of a diffuser according to a fourth embodiment; Figure 6 is a sectional elevation of a conventional venturi tube; Figure 7 is an isometric view of a venturi according to a fifth embodiment; Figure 8 is an isometric view of a venturi according to the sixth embodiment;
Detailed Description of Specific Embodiments
The invention is directed to a flow controller, the structure of which is configured to cause the rate of a fluid flow to be altered during passage through the controller. Each of the embodiments is directed to a flow controller adapted to alter the rate of flow of a fluid.
It has been found that all fluids when moving under the influence of the natural forces of Nature, tend to move in spirals or vortices. These spirals or vortices generally comply to a mathematical progression known as the Golden Ratio or a Fibonacci-like Progression.
Each of the embodiments serves, in the greater part, to enable fluids to move in their naturally preferred way, thereby reducing inefficiencies created through turbulence and friction which are normally found in apparatus commonly used for propagating fluid flow. Previously developed technologies have generally been less compliant with natural fluid flow tendencies.
The greater percentage of the surfaces of the flow controller of each of the embodiments described herein are generally designed in the greater part, in accordance with the Golden Section or Ratio or are designed to ensure the volume of fluid flowing through the flow controller expands or contracts in the greater part in accordance with the Golden Section and therefore it is a characteristic of each of the embodiments that the flow controller provides a fluid pathway which is of a spiralling configuration and which conforms at least in greater part to the characteristics of the Golden Section or Ratio. The characteristics of the Golden Section are illustrated in Figure 1 which illustrates the unfolding of the spiral curve according to the Golden Section or Ratio. As the spiral unfolds the order of growth of the radius of the curve which is measured at equiangular radii (eg E, F, G, H, I and J) is constant. This can be illustrated from the triangular representation of each radius between each sequence which corresponds to the formula of a: b = b: a+b which conforms to the ratio of 1: 0.618 approximately and which is consistent throughout the curve.
It is a characteristic of each of the embodiments that the curvature of the surfaces which form the flow controller takes a two dimensional or three dimensional shape equivalent to the lines of vorticity or streak lines found in a naturally occurring vortex. In general, the curvature of the surfaces substantially or in the greater part conform to the characteristics of the Golden Section or Ratio and that any variation in cross-sectional area of the flow controller also substantially or in greater part conforms to the characteristics of the Golden Section or Ratio. In at least some of the embodiments, the curvature of the active surface conforms to an equiangular spiral. Furthermore it has been found that the characteristics of the Golden Section or Ratio are found in nature in the form of the external and internal configurations of shells of the phylum Mollusca, classes Gastropoda and Cephalopoda and it is a common characteristic of at least some of the embodiments that the fluid pathway defined by the flow controller corresponds generally to the external or internal configuration of shells of one or more of the genera of the phylum Mollusca, classes Gastropoda and Cephalopoda.
It has been found that it is a characteristic of fluid flow that, when it is caused to undergo a fluid flow through a pathway having a curvature substantially or in greater part conforming to that of the Golden Section or Ratio that the fluid flow over the surfaces is substantially non-turbulent and as a result has a decreased tendency to cavitate. As a result, fluid flow over the surface is more efficient than has been encountered in previous instances where the pathway does not substantially or in greater part correspond to that of the Golden Section. As a result of the reduced degree of turbulence which is induced in the fluid in its passageway through such a pathway, the flow controllers according to the various embodiments can be used for conducting fluid with a greater efficiency than has previously been possible with conventional flow controllers of equivalent dimensional characteristics.
It should be noted that it is impossible to illustrate the features of the embodiments by simple two-dimensional drawings. To assist the reader's understanding of the embodiments, the outer surfaces of the embodiments in the drawings are depicted in a way whereby they would correspond with the inner surfaces, such as would be the case if the walls of the embodiments are of constant thickness. In this way some concept of the helical/spiral configurations of the inner surfaces is conveyed. In practical fluid flow control devices, the configuration of the outer surface is not of significance to the embodiments and thus the outer surface could be configured as a simple surface such as a cone., leaving the inner surface complex as suggested in these drawings.
The first embodiment takes the form of a nozzle as shown in Figure 2. The nozzle 11 has a nozzle body 21, an outlet 22 and an inlet 23 which is adapted to be joined to a duct (not shown) such as a pipe, hose or similar providing a source of fluid under pressure. The nozzle body 21 has an internal surface 25 which reduces in cross-sectional area to the outlet 22. In addition, the internal surface of the nozzle may be seen to twist in a combination helical manner and spiralling manner between the input and the output. As indicated above, this twist is in a configuration which provides an active surface which conforms at least in greater part to the characteristics of the Golden Section or Ratio. It will be seen that as a result of the twist, fluid flowing in the nozzle is caused to be given a rotational motion about the longitudinal axis of the nozzle to thereby induce vortical motion in the fluid.
As a result of the vortical motion, the turbulence and friction in the nozzle are reduced considerably from that observed in a conventional nozzle having a simple conical internal surface.
A second embodiment takes the form of a nozzle as shown in Figure 3. The second embodiment is of substantially similar construction to that of the first embodiment, and therefore in the drawings like parts are denoted with like numerals. The second embodiment differs from the first only in the particular design of the nozzle in that it is relatively longer and has greater twist. By varying the parameters of the nozzle, the formation of the vortical flow emitted from the nozzle outlet can be controlled. In certain applications, it will be desirable for the outlet to comprise a narrow vortical stream while in others, a diverging stream will be required to promote mixing of the output with the surrounding fluid.
A third embodiment takes the form of a nozzle as shown in Figure 4. In this embodiment, the twist in the flow surfaces causes the direction of flow to be diverted transversely to that of the incoming flow stream. This redirection is achieved without significant loss because the internal surface of the nozzle is still configured to conform at least in greater part to the characteristics of the Golden Section or Ratio. As a result, turbulence is substantially avoided.
It will be appreciated that a whole class of embodiments are possible whereby the output flow is directed obliquely relative to the direction of the input flow stream.
A fourth embodiment takes the form of a diffuser as shown in Figure 5. It may be appreciated that a diffuser may comprise a flow controller substantially identical to a nozzle but with direction of flow reversed. In this regard, the diffuser of Figure 5 corresponds with the nozzle of Figure 2 but having an internal surface 25 which increases in cross-sectional area to the outlet 22.. Therefore, in the drawings like numerals are again used to depict like features. As with the nozzle, while the diffuser of Figure 4 will induce vortical motion in the fluid flow, the precise characteristics of the output flow can be controlled by varying the design properties of the diffuser while maintaining the inner surface to conform at least in greater part to the characteristics of the Golden Section or Ratio.
It has been previously been noted that the cross-sectional area of the previous embodiments varies between the inlets to the outlets ; for the nozzles, the area decreasing and for the diffusers, the area increasing. In a further development of the previous embodiments, it has been found advantageous, at least in certain circumstances to vary the incremental volume of the controller along the fluid pathway in a manner that conforms to the characteristics of the Golden Section or Ratio. To take advantage of this aspect, further embodiments of the fluid flow control devices as previously described are configured to conform with this constraint. As a result, the volume of fluid flowing through the flow controller expands or contracts in the greater part in accordance with the Golden Ratio.
A fifth embodiment takes the form of a modified venturi tube as shown in Figure 7. The modified venturi tube is best appreciated by comparison with a conventional venturi tube which is depicted In Figure 6. In the conventional venturi tube of Figure 6, a venturi 51 comprises an inlet 52, an outlet 53 and a constricted region 54. The constricted region 54 comprises an entry 55, an exit 56 and a region of maximum constriction 57. In the drawings, the flow is represented by flow lines 58.
When fluid is caused to flow into the inlet 52 of venturi 21, it is affected by the entry 55 wherein the diameter of the fluid pathway is progressively reduced until the region of maximum constriction 57 is reached. This constriction within the fluid pathway causes the speed at which the fluid is travelling to be increased. In accordance with well known laws of thermodynamics, this increase in fluid speed is accompanied by a reduction in pressure of the fluid. Subsequent to the region of maximum constriction 57, the fluid flow is affected by the exit 56 wherein the diameter of the fluid pathway is progressively increased to the outlet 53. In the exit 56, the fluid is progressively slowed.
It is known that the energy losses at a venturi are very significant. As mentioned above, these losses are caused both by friction and turbulence. In particular, it is well known that while the performance of a venturi can be increased by increasing the ratio of the inlet diameter relative to the diameter of maximum constriction 57, it is also known that in practice that any gains achieved by so reducing the region of maximum constriction are rapidly cancelled by the increased losses which result.
As can be seen in Fig. 7, the modified venturi 61 comprises an inlet 62, an outlet 63, a region of maximum constriction 64, an entry 65 and an exit 66. It will be readily perceived that these portions conform generally to corresponding portions of the conventional venturi tube of Figure 6. In contrast however, the entry 64 and exit 65 are specifically designed to induce the fluid to move in accordance with the laws of Nature. As mentioned previously, the flow controller is designed with a pathway having a curvature substantially or in greater part conforming to that of the Golden Section or Ratio. The fluid is thereby induced into vortical flow the greater part of which conforms to the Golden Section or Ratio. The energy losses caused as a result of this vortical flow are considerably lower than those which result from a conventional venturi.
As a result of the considerably reduced energy losses caused by the modified venturi of the fifth embodiment, the apparatus may be used more effectively than previously has been possible. Firstly, it is possible to increase the ratio of the area of inlet relative to the area of maximum constriction. This increases the relative pressure difference that may be generated between the inlet and the region of maximum constriction. This broadens the scope of use of the device.
A sixth embodiment takes the form of a modified venturi tube as shown in Figure 8. The sixth embodiment, although somewhat different in appearance, operates in substantially the same manner as that of fifth embodiment and so, in the drawings, like parts are denoted with like numerals. The sixth embodiment again comprises a duct, the area of cross-section of which reduces from an inlet to a portion of maximum constriction, and then increase to the outlet. The difference between the sixth embodiment and the fifth is that in the fifth embodiment the flow induces a vortex which has an axis of rotation which is co-linearly aligned with the central axis of the inlet, whereas in the sixth embodiment, the axis of rotation of the vortex is disposed substantially transversely to the central the axis of the inlet.
It has been noted previously that in the embodiments of the modified venturi tube, the cross-sectional area of the duct varies along the flow path, decreasing in the entry and increasing in the exit. As in the examples of the nozzles and diffusers, it has been found advantageous, at least in certain circumstances to vary the incremental volume of the controller along the fluid pathway in a manner that conforms to the characteristics of the Golden Section or Ratio. To take advantage of this aspect, further embodiments of the modified venturi tubes as previously described are configured to conform with this constraint. As a result, the volume of fluid flowing through the entry and exit of the venturi contracts or expands in the greater part in accordance with the Golden Ratio.
It has been found that, in at least certain configurations of the embodiments, the arrangements promote substantially radial laminar flow and it is believed that this assists the efficiency of the fluid flow within those arrangements.
It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiments described above.
Throughout the specification, unless the context requires otherwise, the word "comprise"or variations such as"comprises"or"comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers
US7862302
FLUID CIRCULATION SYSTEM
FLUID CIRCULATION SYSTEM
Field of the Invention The present invention relates to the field of fluid mechanics and more particularly to the circulation within a body of fluid. More particularly, this invention seeks to provide an improved system of circulation within a body of fluid.
Background Art
There are many applications wherein it is desirable to cause circulation within a body of fluid. Common reasons for providing circulation are for mixing, to prevent stratification and to aerate a body of liquid. Examples of these will be discussed later within this specification.
A large number of methods have been devised to cause the desired circulation. In one example, in the case of liquids, it is common to hold the liquid body within a cylindrical tank having its central axis oriented vertically and to cause the liquid to be moved within the tank by the action of an impeller driven by a motor. Many other means have been devised to cause the body of liquid to rotate. Nevertheless, these techniques require the expenditure of significant energy and often give rise to associated problems. Many of these inefficiencies and problems arise because such systems have not been designed to cause the fluid to be circulated in accordance with the natural flow tendencies found in nature.
In nature, fluid flow is essentially turbulent or vortical. A vortex ring cross- sectionally rolls, much like a wheel, rather than slides. Famed hydrodynamisist, Reynolds once stated, in reference to ring vortices, that"Nature prefers to roll rather than glide".
It is this feature that greatly contributes to ring vortex efficiency.
Disclosure of the Invention
This invention is specifically designed to cause circulation of fluid within a fluid body in the form of vortices and preferably, single or multiple vortex rings.
Accordingly, the invention resides in a fluid circulation system wherein circulation is caused within a body of fluid by establishing and maintaining a vortex within the fluid.
According to a preferred feature of the invention the fluid circulation is in the form of a singular or multiple ring vortices within the fluid.
According to a preferred feature of the invention, the circulation is caused by means of the rotation of an impeller located within the fluid.
According to a preferred feature of the invention, the impeller is designed in accordance with the Golden Section or Phi geometry.
According to a preferred feature of the invention, the impeller is designed substantially in accordance with the Golden-Section-like centre or parts of a volute or other seashell.
According to a preferred feature of the invention, the form of the impeller corresponds with the flow lines, streamlines, or lines of vorticity within the funnel or central section of the ring vortex.
According to a preferred feature of the invention, the impeller is provided with an active surface having a configuration substantially conforming to at least one logarithmic curve of the Golden Section According to a preferred embodiment, the active surface substantially conforms to the Golden Section along the X-axis or along the Y-axis or along the Z-axis.
According to a preferred embodiment, the active surface substantially conforms to the Golden Section along two of the X and Y and Z axes. According to a preferred embodiment, the active surface substantially conforms to the Golden Section along the X, Y and Z axes.
According to a preferred embodiment, the fluid body comprises a body of liquid in a substantially cylindrical tank oriented with its central axis disposed upwardly, wherein the impeller is positioned within the liquid to rotate about an axis of rotation substantially co-axially aligned with the central axis of the tank.
According to a further aspect, the invention resides in a mixing system for a body of liquid contained within a tank, the system comprising an impeller of the type described above wherein the impeller is positioned within the liquid to cause circulation of the liquid within the tank. According to a preferred embodiment, the tank is substantially cylindrical and oriented with its central axis disposed upwardly and the impeller is oriented to rotate about an axis of rotation substantially co-axially aligned with the central axis of the tank to cause the circulation of the liquid to be in the form of a ring vortex.
According to a preferred embodiment, the impeller may be mounted substantially horizontally.
According to a preferred embodiment, the base of the cylindrical tank is curved.
According to a preferred embodiment, the base of the cylindrical tank is a spherical section.
According to a preferred embodiment, the tank may be other than cylindrical.
According to a further aspect, the invention resides in a water remediation system adapted for a reservoir of water, the water remediation system comprising an impeller of the type previously described adapted to rotate within the water to thereby establish circulation of the water in the form of a ring vortex.
According to a preferred feature of the invention, the axis of rotation of the impeller is upwardly disposed.
According to a preferred embodiment, the axis of rotation of the impeller is substantially vertical.
According to a preferred embodiment, the reservoir of water is a water tower associated with a reticulated supply and the circulation of water is adapted to disrupt or prevent the formation of stratification within the water body.
According to a preferred embodiment, the reservoir of water is a pond and the circulation of water is adapted to promote aeration of the whole body of water.
According to a preferred embodiment, the body of fluid is a gas.
The invention will be more fully understood in the light of the following description of several specific embodiments.
Brief Description of the Drawings
The description is made with reference to the accompanying drawings, of which: Figure 1 is a diagrammatic representation of a ring vortex; Figure 2a is an isometric view of an impeller, typical of those used in the embodiments; Figure 2b is a side elevation of an alternative impeller to that shown in Figure 2a typical of those used in the embodiments; Figure 3 is a diagrammatic representation of the interaction of the impeller of Figure 2a with a body of fluid as it rotates, in accordance with the embodiments;
Figure 4 is a diagrammatic view of a tank of liquid being circulated by the impeller of Figure 2a in accordance with the first embodiment; Figure 5 is a diagrammatic view of a water tower being circulated by the impeller of Figure 2a in accordance with the second embodiment; Figure 6 is a diagrammatic view of pond of liquid being circulated by the impeller of Figure 2a in accordance with the third embodiment.
Detailed Description of Specific Embodiments
The applicant has previously disclosed rotors designed in accordance with the principles of nature in international applications PCT/AU96/00427 (WO 97/03291) which has matured to US 5, 934, 877 and others, PCT/AUOO/01438 (WO 01/38697) and PCT/AU03/00002 (WO 03/056139). The rotors of each of the embodiments described in those specifications are generally designed in all respects, substantially in accordance with the Golden Section or the Golden-Section-like centre or parts of a volute or other seashell and therefore it is a characteristic of each of the embodiments that the rotor provides a fluid pathway which is of a spiraling configuration and which conforms at least generally to the characteristics of the Golden Section. While it was envisaged that the rotors disclosed in these specifications would be suitable for use in pumps, turbines, fans, propellers and the like, it has been discovered that where at least certain embodiments are permitted to rotate at a fixed location in a body of fluid, the fluid is caused to circulate and that after a short period of time, the circulation will take the form of a ring vortex.
A ring vortex is a mechanism with interesting properties and an example is diagrammatically illustrated in Figure 1. In a free environment, the ring vortex 11 has a doughnut shape with a central funnel region 12. The vortex lines 13 attempt to give an impression of the fluid flow within the ring vortex although it must be appreciated that this is impossible via a two dimensional illustration. A smoke ring is an example of a ring vortex. Once established, a ring vortex requires very little energy input to maintain it indefinitely. It also has a flow structure wherein the fluid flow is slowest at the outer perimeter. Thirdly, because of its peculiar, multi- directional flow, it is highly effective and efficient at mixing the fluid. Advantage is taken of these properties in the embodiments described below.
It can also reach a resonance point and accumulate energy which thereby, over time, may reduce the energy input required to maintain the ring vortex.
Each of the embodiments of the present invention comprises a system for inducing within a body of fluid a circulation that follows the path of a ring vortex. A ring vortex is nature's preferred, most common, most efficient manner of circulatory flow of a fluid. It is a mechanism that is highly efficient compared with other patterns of flow and has several advantageous properties ;-as are-discussed-above.
Once found, its inertia becomes integrally part of the"flow device"comprising the liquid flow field and impeller with all sharing the same geometry of movement that is essentially a radial laminar flow path.
While it is possible to induce a body to circulate as a ring vortex in a number of different ways, it is a common feature of the embodiments that they are caused to circulate by means of an impeller designed in accordance with the principles disclosed by the applicant in his previous applications as mentioned above, having surfaces designed in accordance with the Golden Section. it is a characteristic of such an impeller that the curvatures of the surfaces, which form the impeller, take a two-dimensional or three-dimensional form which substantially conforms with the characteristics of the"Golden Section"and any variation in cross-sectional area also conforms substantially to the characteristics of the"Golden Section".
Examples of impeller that has been found to be particularly suitable shown in Figure 2a and 2b. In these, this impeller is designed in the form of a whorl and comprises an impeller 21 having twin vanes 22 which have a helical configuration with active surfaces 23 and 24 substantially conforming to that of the"Golden Section"and which is adapted to be supported upon a central shaft 25 to be driven by a motor. The configuration of the vanes of these impellers correspond to the lines of vorticity of the central or"funnel"portion of a ring vortex and it is this fact that makes such an impeller effective in producing a ring vortex. It should be noted that alternative configurations of the impeller may also be used, such as an impeller with a single vane, or multiple vanes with active surfaces configured substantially in accordance with the Golden Section. These active surfaces may substantially conform to the Golden Section along the X-axis or along the Y-axis or along the Z- axis, along two of the X and Y and Z axes, or along the X, Y, and Z axes.
When the impeller is first caused to rotate within a body of fluid, it induces both an axiai fibw to the fluid and"a rotatioha ! fibw. tnitiaiiy, the impetier creates a high degree of turbulence as the body of fluid is initially stationary. However, as the impeller is allowed to operate for a little time, the fluid is caused to circulate, as indicated diagrammatically in Figure 3. Because the impeller is designed to conform to the natural flow of the fluid, a progressively higher proportion of energy input by the impeller is imparted to the fluid as kinetic energy rather than turbulence as the fluid body accelerates and the fluid is thereby induced to flow in its natural way which is in the form of a ring vortex. Once the ring vortex is established sufficiently, the impeller shows little or no tendency to cause cavitation over a wide range of operating speeds. This is. in contrast to a conventional impeller where the operation at a speed above its designed level rapidly leads to cavitation.
In the first embodiment of the present invention as diagrammatically represented in Figures 4 there is depicted a body of liquid 31 held in a cylindrical tank 32, the tank 32 being oriented with its central axis vertical. Within the tank 32, there is mounted a submersible motor 33 having an impeller 34, the axle of the motor and impeller being substantially co-axially aligned with the central axis of the tank 32. The motor 33 may be conveniently mounted to the base of the tank 35. As mentioned above, the impeller 34 is designed so that its active surfaces conform to the Golden Section as shown in Figure 2a or Figure 2b. Operation of the impeller 34 causes the fluid to circulate as a ring vortex and indicated by the flow lines 36, as discussed above. If the liquid 31 is a mixture which must be mixed homogeneously, such mixing is achieved efficiently.
The advantages of the present system will be better appreciated by a comparison with a conventional mixing system of similar arrangement. Such a system again uses a cylindrical tank having a motor driving an impeller. However, the impeller of such a system is designed to cause the body of liquid to rotate about the central axis of the tank. This results in a number of problems.
In such a system, the speed of liquid flow is greatest at the perimeter of the fluid body, that is ;-at the-wall of-the--tank:- As-a result, considerable energy is expended due to frictional losses in moving the liquid relative to the wall. In contrast, in a ring vortex, the speed of liquid flow is at its lowest at the perimeter, that is, at the tank wall, so that frictional losses are minimised. Also as a result of rotating flow in conventional systems, the water tends to"climb up"the wall, at the perimeter as a result of the"centrifugal"force. When fluid flow is in accordance with a ring vortex as in the case of the embodiments, the surface level remains substantially constant, around the edges. It is to be noted that, while in both cases, the water level is reduced at the centre, the fluid dynamics involved is very different. It should be noted that, at least in a relatively small tank, once the ring vortex is established and excessive power is input it is possible to establish a rotating wave which circulates around the surface of the liquid. The fluid dynamics of this wave motion are not yet fully understood but it is to be recognized that it is the wave that rotates, not the liquid itself. In addition, mixing is inefficient in a conventional system. In such a system, once rotational motion is established, the liquid tends to rotate as a fixed mass like a wheel with little relative movement within the liquid. This is known as solid body rotation. Mixing must be continued for a relatively long time. In contrast, relative fluid movement is inherent within a ring vortex and mixing time is minimised.
The conventional mixing process requires substantial power to get it started. This requires that the motor be sized accordingly. In certain chemical and pharmaceutical mixing processes, it is necessary to mix large batches of material over a prolonged period, in the order of one month. It has been found that in some cases, if the process is stopped before the completion of mixing, for instance due to power failure, it has been found impossible to restart the process because of limiting start-up inertia. The motor is not powerful enough to restart so that the whole batch must be scrapped. The other alternative, historically, is to fit a larger motor in the first place. Obviously, this results in considerable economic loss. In contrast, mixing by means of the present invention does not require excess power for starting. The ring vortex is an energy reservoir. As energy is added, it is stored in the vortex ring. Therefore, at starting, energy is added in progressively, until the ring vortex is functioning at a level such that the energy dissipated in losses in the system is similar to the energy being input.
Clearly, in any real system some losses will exist. In a simple example of the embodiment, where the tank is of cylindrical shape, it is believed that some losses occur because of the abrupt change between the floor and the wall. It is believed that such losses are reduced by providing a tank with a curved base, such as a spherical section, rather than a flat base. Nevertheless, even in a standard cylindrical tank, an effective ring vortex can be established with high efficiency.
Indeed, it is quite possible to establish fluid flow in the form of a ring vortex even in a tank which is non-cylindrical, even of very irregular shape.
It is a peculiar characteristic of the system that a ring vortex will be established whether the liquid is made to rise at the centre or whether it is made to fall, with only the direction of internal flow of the ring vortex being reversed. It is believed that there may be some applications where flow in a particular of the two directions may be slightly advantageous.
It is also believed that there are applications, particularly in relatively shallow tanks where the performance will be improved by an appropriate positioning of the impeller between the base and the liquid surface.
In a second embodiment as shown in Figure 5, there is provided a water remediation system for a water tower of the type used in water reticulation systems for municipal supplies. Water towers are widely used by water authorities as a means to provide an adequate supply of water at the desired pressure during periods of peak demand. During non-peak periods, water is pumped by a pumping station, with a portion of the water meeting the demand and a portion being pumped into an elevated water tower. During peak periods when the demand exceeds the capacity of the pumping system, additional supply is obtained from the water tower.
It is normal design with such towers for water to be input and withdrawn through the same pipe which is connected at or near the floor of the water storage. However, this leads to a problem. Through much of the year, the volume of water added to the tank and withdrawn from the tank is only a small proportion of the total capacity.
At least in the warmer months, it is normal for water to be warmed above the temperature of the water being provided by the supply. Water which is added to the tank at such times is added at the base of the tank, and, as it is cooler than the general body of water in the tank, will remain adjacent to the base of the tank.
When water is removed from the tank it is the cool water at the base of the tank which is removed first. As a result, stratification of the water body occurs and the water in the upper levels of the tank is not circulated, nor withdrawn and replaced by fresh water, as is the case for the lower water. This stagnation results in the upper water fouling. To prevent such fouling, supply authorities have found it necessary to add chemicals, which is relatively expensive and also undesirable from the perspective of water quality. Alternatively pumps or paddle agitators can be used but are far less efficient than this invention as they create turbulent flow instead of a primary ring vortex.
According to the second embodiment, an impeller 42 of the type described with respect to the first embodiment and driven by a suitable motor is positioned centrally within the water tower 41, the rotational axis of the impeller 42 and motor being aligned vertically. The impeller 42 may be positioned at a relatively low level within the water body so as to be operable without problem when the water level is low. A level switch 43 is provided within the circuitry of the motor to isolate the motor when the water level in the water tower 41 drops too low, thereby preventing the motor from operating when the impeller 42 is not covered by water. As a result of the operation of the impeller 42, a ring vortex will be established within the water body, ensuring circulation of the water held within the water tower at very low power consumption levels. Due to this circulation, stratification of the water will either be prevented or dispersed. As a result of the efficiencies of the ring vortex and in the impeller designed substantially in accordance with the Golden Section, it is expected that a motor of power in the range of 20 watts to 100 watts will be adequate for most water towers. The expense of operating such a motor is considerably less than the cost of adding chemicals to control the fouling. The power use is so low that solar power is an economic option.
In a third embodiment as shown in Figure 6, there is provided a water remediation and/or maintenance system for a pond, such as may be found in municipal parks. It is well known that such ponds suffer fouling due to lack of aeration which results in the death of fish and aerobic plants and the build up of unpleasant mould, fungi, botulism, and mosquito breeding. With a still pond, water stratifies with the cold water remaining at the bottom and the warmer water at the top which accentuates the problems. Attempts to reduce the fouling by aeration or other means have been only partially effective because they do not fully circulate the water but rather rely on diffusion of compressed air into the stagnant lower layers. Because of the stratification, this diffusion is not very successful.
In the third embodiment, a pond 51 is provided with a small motor 52 driving an impeller 53 of the type described for the first embodiment. The motor 52 is located approximately in the centre of the pond 51 with its axis vertical and the impeller 53 submerged somewhat in the pond water. Water circulation is established by running the motor 52 continuously. In doing so, after some time, fluid flow adopts the pattern of a ring vortex. As a result, the pond water circulates and mixes the whole body of water of the pond 51. The circulation removes the stratification and results in the aerated surface layer being continuously mixed with all other water, thereby providing aeration to the total water body. These advantages displayed by the embodiment are realized with a motor of very small, relative size. In testing, rejuvenation of a pond having a surface area of approximately one acre (1.7 million gallons) was achieved within two weeks by operation of a motor of 40 watts. It is believed that even lower power will be required to maintain the pond in a healthy state. If this power is provided from mains supply, the electrical cost would be less than $50.00, annually, significantly less and more effective than applying chemical treatments. In addition, while the circulation will effect the whole pond, due to the nature of fluid flow within the ring vortex, the flow at the perimeter of the pond will be very slow and indeed, almost imperceptible to the naked eye. Thus, the fluid circulation will not cause an erosion problem about the pond edges.
In an alternative test, a one-half acre, 16-foot deep, million-gallon water supply reservoir was fully mixed in 20 hours with a 24-watt motor.
In one adaptation of the third embodiment, the motor and impeller assembly could be mounted to a stand which also supports a photoelectric panel to provide the power to drive the motor. This arrangement could be combined with a battery to provide continuous flow. Alternatively, it is believed that the water will be maintained at a satisfactory quality level in many environments by operation of the impeller intermittently, only when there is sufficient sunlight to drive the motor. By this arrangement, the need to provide mains electrical power supply to an installation in the centre of a large body of water is removed.
In another adaptation of the third embodiment, the motor, impeller and photoelectric panel are supported by a floatation device and the whole assembly moored to the pond floor by a suitable anchoring device. Such an arrangement would be suitable for a relatively deep pond, where it was impractical to support the assembly from the pond floor, or in a pond in which the level of water fluctuates significantly.
It should be noted that, in the case of the embodiments, while the best performance can be expected to be achieved when the impeller is positioned centrally relative to the pond or to the vertical axis of the tank or the water tower, it has been found that the systems operate effectively even when the funnel portion of the ring vortex is disposed significantly away from the respective central feature.
In the case of the various forms of the third embodiment, it will be recognized that the many ponds have a shape in plan that is very irregular. Indeed in some cases, the pond may comprise two or more main pools linked by a relatively narrow channel. It will be recognized that in these circumstances, it may be appropriate to operate more than one impellor, positioned to establish more than one vortex. It will be important in such situations to ensure that the vortices cooperate with each other by creation of vortices having correct rotations.
A further application of the third embodiment is in relation to a fish farm. The relatively low water speed across most of the pond, except in the vicinity of the funnel region while providing a high level of circulation and aeration make the embodiment an ideal environment for the farming of fish. Interestingly, it has been observed that fish will even pass through the funnel portion of the ring vortex without any noticeable distress.
The impeller expands logarithmically from inlet to outlet and thereby provides the following unique benefits: it will not harm fish and other organisms and does not easily foul from weeds or plastics as other conventional devices do.
The thorough circulation and excellent aeration of the fluid body as demonstrated in the third embodiment also render the process most suitable for sewerage treatment facilities. In each of the embodiments described, if the impeller is rotated at higher speeds it creates a vortex evacuation tube in the centre of the liquid movement. It will draw this tube of air right down to the impeller and vigorously disperse air throughout the liquid in an efficient and homogeneous way. This is a very inexpensive way to aerate liquids and has particular relevance to sewerage treatment, fish farms and many industrial applications.
It has been found that, in the various embodiments described above, the height and width of the ring vortex can be controlled by adjusting the stagger angle of the impeller.
In certain applications, it has been found desirable to produce the ring vortex by positioning the impeller to rotate about a substantially horizontal axis. Indeed, a ring vortex can be set up with the axis of the impeller oriented at other angles, intermediate vertical and horizontal. The application will determine the optimum angle.
The above embodiments identify but a few of the potential applications to which the invention may be adapted. By making use of the ring vortex, the applications get the benefits derived from using the natural flow pattern. It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiments described above.
Throughout the specification, unless the context requires otherwise, the word "comprise"or variations such as"comprises"or"comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
US2008265101
Vortex ring generator
Vortex ring generator
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of fluid mechanics and more particularly to the flow of a fluid relative to a body. More particularly, this invention seeks to reduce drag on a body or fuselage during relative movement of the body with respect to a fluid.
[0004] The invention is described herein by reference to its use in respect to any mobile body or fuselage, such as, including, but not limited to, projectiles, missiles, torpedoes, submarines and aircraft. However, the invention is not restricted to mobile fuselages, but may also be used to reduce drag on stationary bodies such as buildings, bridge pilings, and fixed obstacles in watercourses, airways or other fluid flow fields. Such applications are intended to be within the scope of the invention although not specifically described herein.
[0005] 2. Background Art
[0006] The greatest obstacle to obtaining optimum efficiency in streamlining a fuselage is surface friction. This can be in several forms but typically is one of or a combination of boundary layer drag, skin friction, viscosity, surface tension, cavitation and turbulence.
[0007] Existing technologies seek to reduce this drag and optimise the energy efficiency of a moving body or fuselage by altering its surface to be as smooth as possible with the least possible protuberances or alternatively to roughen the smooth surface or to give it a rippling surface similar to that of a shark, dolphin or golf ball. The objective is to minimise the effects of drag from fluids flowing past. Another attempt to cut drag has included the fitting of small vortex generators to wings and other parts of the fuselage. A further attempt has been to fit a spike-like protuberance extending forwardly in the direction of travel of the fuselage through the fluid.
[0008] In general, it has been an objective of these attempts to maintain straight, laminar flow over the body of the fuselage, and to suppress separation or turbulence as far as is possible. Alternatively, through the use of dimpled or roughen surfaces and vortex generators, the objective has been to create myriad eddies in close proximity to the fuselage surface to break up the boundary layer. Essentially, all these approaches are designed to assist fluids slide past the body with a minimum of friction.
SUMMARY OF THE INVENTION
[0009] A first embodiment of the claimed invention provides for a vortex ring generating system inclusive of a body and spiraled surfaces affixed to the body. The body propels fluid from a forward portion to a rear portion when in motion. The spiraled surfaces are alternately concave and convex surfaces. A portion of each surface conforms substantially to a logarithmic spiral, wherein the radius of the logarithmic spiral measured at equiangular radii unfolds at a constant order of growth. The spiraled surfaces commence near the forward portion of the body and terminate near a rear portion of the body. The surfaces generate a vortex ring surrounding the body as the body propels the fluid from the forward portion toward the rear portion.
[0010] A second embodiment of the claim invention provides for a vortex ring generator that includes a mobile body and vanes extending outward from the body, which includes a nose and a tail. The vanes commence near the nose and end near the tail. The vanes define a spiral path around the body and are alternately configured as concave and convex surfaces. A portion of each surface of the plurality of vanes conforms substantially to a logarithmic spiral, wherein the radius of the logarithmic spiral measured at equiangular radii unfolds at a constant order of growth. The vanes generate a vortex ring with respect to a fluid incident to the mobile body and propel the fluid from the nose of the body toward the tail of the body.
[0011] A third claimed embodiment of the present invention includes a mobile body configured to reduce drag in a flowing fluid. The mobile body includes an axis aligned with a direction of the flowing fluid relative to the mobile body. The mobile body includes a nose and tail. A vortex ring generator coupled to the
body includes a helical vane disposed around a central axis aligned with the axis of the body, the vane extending from the nose to the tail of the body. The vane includes alternately configured concave and convex surfaces. A portion of the helical vane conforms to a logarithmic curve, wherein the radius of the logarithmic curve measured at equiangular radii unfolds at a constant order of growth. The vortex ring generator induces a vortex ring around the body whereby the drag of a flowing fluid against the body is reduced as the body propels the flowing fluid along the axis aligned with a direction of the flowing fluid relative to the body.
[0012] A method for reducing drag on a mobile body in a fluid is provided and claimed. The method includes configuring the mobile body with spiraled surfaces affixed to the mobile body. The spiraled surfaces are alternately configured as concave and convex surfaces. A portion of each of the spiraled surfaces conforms substantially to a logarithmic spiral, wherein the radius of the logarithmic spiral measured at equiangular radii unfolds at a constant order of growth. The spiraled surfaces commence near the forward portion of the mobile body and terminate near the rear portion of the mobile body. The spiraled surfaces induce the formation of a vortex ring surrounding the mobile body. The mobile body is then subject to a fluid. Vortex rings are then generated to reduce drag on the mobile body as the fluid flows over the mobile body, the fluid being propelled by the mobile body.
[0013] A further claimed method is for generating a vortex ring to reduce drag on a mobile body in a fluid. The body is configuring with spiraled surfaces affixed to the body. The spiraled surfaces are alternately configured as concave and convex surfaces. A portion of each of the spiraled surfaces conforms substantially to a logarithmic spiral, wherein the radius of the logarithmic spiral measured at equiangular radii unfolds at a constant order of growth. The spiraled surfaces commence near the forward portion of the body and terminating near the rear portion of the body. The body is subjected to a fluid and rotated, which propels the fluid from the forward portion of the body toward the rear portion of the body. The rotation of the body generates a vortex ring. As a result, drag is reduced on the body as the fluid flows from the forward portion of the body toward the rear portion of the body.
[0014] In a final claimed embodiment, a vortex ring generator comprising a body and a surface is provided. The body is subjected to relative translational movement with a fluid along a line of movement. The body has no substantial rotational movement about an axis parallel to the line of movement. The surface is three dimensional and spiraling in form and coupled to the body. A portion of the surface conforms to a logarithmic curve. The surface generates a vortex ring in the fluid in relation to the body, the vortex ring having an axis substantially parallel to the line of movement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The description is made with reference to the accompanying drawings, of which:
[0016] FIG. 1 illustrates the form of the Golden Section;
[0017] FIG. 2 is a side elevation of a vortex ring generator according to the first embodiment;
[0018] FIG. 3 is a front end view of a vortex ring generator according to the first embodiment;
[0019] FIG. 4 is a rear end view of a vortex ring generator according to the first embodiment;
[0020] FIG. 5 is a side elevation of a vortex ring generator mounted to a body according to the first embodiment;
[0021] FIG. 6 is a side elevation of a vortex ring generator applied to a body according to the second embodiment;
[0022] FIG. 7 is a front end view of a vortex ring generator applied to a body according to the second embodiment
[0024] FIG. 9 is a front end view of a vortex ring generator applied to a body according to the third embodiment;
[0025] FIG. 10 is a diagrammatic representation of the flow of vortex rings around a body having vortex ring generator according to the first and third embodiments;
[0026] FIG. 11 is a diagrammatic representation of the flow of vortex rings around a body having vortex ring generator according to the second embodiment;
[0027] FIG. 12 is a diagrammatic representation of the generation of a vortex ring around by vortex ring generator according to the first embodiment.
DETAILED DESCRIPTION
[0028] Each of the embodiments comprises a vortex ring generator associated with a body and adapted to generate a vortex ring in the fluid moving relative to the body. In each embodiment, the vortex ring generator comprises a fluid pathway having an active surface adapted to influence the flow of the fluid to form the vortex rings flowing past the body.
[0029] As stated previously all fluids when moving under the influence of the natural forces of Nature, tend to move in spirals or vortices. These spirals or vortices generally comply with a mathematical progression known as the Golden Ratio or a Fibonacci like Progression.
[0030] The greater percentage of the surfaces of the active surfaces of each of the embodiments described herein are generally designed in the greater part, in accordance with the Golden Section or Ratio and therefore it is a characteristic of each of the embodiments that the active surfaces are of a spiralling configuration and which conform at least in greater part to the characteristics of the Golden Section or Ratio. The characteristics of the Golden Section are illustrated in FIG. 1 which illustrates the unfolding of the spiral curve according to the Golden Section or Ratio. As the spiral unfolds the order of growth of the radius of the curve which is measured at equiangular radii (eg E, F, G, H, I and J) is constant. This can be illustrated from the triangular representation of each radius between each sequence which corresponds to the formula of a:b=b:a+b which conforms to the ratio of 1:0.618 approximately and which is consistent through out the curve.
[0031] A characteristic of the embodiments is that not only do the X and Y axis conform to Golden Section geometry, but also the Z axis or depth conforms, that is the vanes conform to the Golden Section in three dimensions.
[0032] It is an objective of the embodiments to duplicate the lines of vorticity found in a ring vortex. To that end, the active surfaces expand or contract logarithmically in any direction in an equiangular, Golden Section spiral. If any two points are taken on the surface of these active surfaces they will bear a ratio to each other of approximately 1:0.618. The active surfaces can be any length or number of rotations. They are specifically designed to match the internal, streamlined flow lines of vorticity of a vortex.
[0033] In the first embodiment, and as shown in FIGS. 2 to 5, the vortex ring generator (11) comprises a set of vanes located at the nose (13) of a body (12). In this specification, the term nose is used to identify the portion of the body which is intended to face the direction from which the relative flow of fluid is approaching the body.
[0034] The vortex ring generator (11) is adapted to generate a vortex ring by influencing the flow of the fluid relative to the body in a way which produces a vortex ring. The vanes comprising the vortex ring generator extend forwardly from the nose of the body and have the configuration of a whorl. Each of the vanes are formed with an internal reactive face (14) which is of a concave configuration and which has a three dimensional curvature of a concave nature whereby the curvature in each direction is in accordance with a logarithmic curve conforming to the Golden Section. As a result, the vanes (11) jointly define a generally concave internal face of the vortex ring generator.
[0035] In addition, each vane has a remote reactive face (15) which is remote from the internal reactive face (14) and which also has a three dimensional curvature of a convex nature whereby the curvature in each dimension conforms with a logarithmic curve according to the Golden Section, and whereby the curvature in each dimension is of the same form as the curvature of the internal reactive face (14) in each dimension. As a result, the remote reactive faces (15) jointly define a generally convex surface of the vanes.
[0036] In an adaptation of the first embodiment, the vortex ring generator is not fixedly mounted to the nose but rather is adapted to rotate coaxially with the axis of the body. In addition, the generator may be driven mechanically to rotate thereby providing propulsion to the body whilst simultaneously generating vortex rings.
[0037] In the second embodiment, as shown in FIGS. 6 and 7, the vortex ring generator comprises a set one or more grooves or flutes (21) in the surface of the body, commencing at or near the nose (23) of the body (22) and ending at or near the tail (24) of the body. The paths of the grooves or flutes along the body spiral around the body in a manner designed to conform to the Golden Ratio.
[0038] In the third embodiment, as shown in FIGS. 8 and 9, the vortex ring generator comprises a set one or more vanes (31) extending outwardly from the surface of the body, commencing at or near the nose (33) of the body (32) and ending at or near the tail (34) of the body. The paths of the vanes along the body spiral around the body in a manner designed to conform to the Golden Ratio.
[0039] The body in each of the above embodiments is ideally designed in accordance with a logarithmic, equiangular, Phi spiral. Its shape is optimally compatible with Phi vortex geometry, which is common to all vortices. In other words the body occupies that space which is seen in the cavitation tube of a visible vortex.
[0040] As depicted in FIG. 11, the body, 13, is accommodated within the core of the vortex, 16. The nose of the body, by use of embodiment one, two or three above exactly fits the geometry of a ring vortex. The body may be cone-shaped with a hollow centre allowing fluid incoming to the vortex ring to travel through its core.
[0041] FIGS. 10 and 11 illustrate the creation of ring vortices, 16, which travel/roll along the body.
[0042] In operation, with relative movement between the fluid and the body, the fluid is engaged by the active surfaces 11, 21 or 31 and commences rotating in a logarithmic vortical fashion. As the fluid engages the active surfaces, the rotary motion creates a low-pressure area at the base of the vortex generator (the interface between the generator and the nose of the body). This reduces the boundary layer drag of the body. A ring and/or potential vortex is established. As can be seen in FIG. 10, the ring vortex rolls up the boundary layer, like ball bearings, along the body walls. In many applications vortex rings will shed and give rise to a stream of shed vortex rings. The wake left behind the body is in the shape of vortex rings.
[0043] FIG. 12 illustrates the vortex ring generator, 11 of the first embodiment creating a ring vortex, 16. To do so, there must be relative motion between the vortex ring generator, 11, and the fluid.
[0044] This motion can be created by rotation of the vortex ring generator; the movement of fluid past a stationary vortex ring generator, or the propulsion of the body and vortex ring generator through the fluid.
[0045] It should be appreciated that the scope of the present invention need not be limited to the particular scope described above.
[0046] Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
SINGLE
OR MULTIPLE BLADED ROTOR
WO03056139
WO03056139
A Single or Multiple Bladed Rotor
Field of the invention
This invention relates to a rotor and in particular a single or multi-bladed rotor. The rotor according to the invention may be one which is intended to induce a fluid flow or alternatively may be one which is intended to be influenced by a fluid flow, resulting in rotation of the rotor as a result of that influence. Examples of the application of the rotor according to the invention comprise use as: a fan blade which is used to generate an air flow ; a turbine blade which is used to generate a fluid flow or to react to a fluid flow ; an impeller for use in a pump or compressor, or one which is reactive to a fluid flow ; a mixer or bioreactor impeller ; or a propeller or jet pump which may be used with watercraft and aircraft.
Background art
The invention comprises a development of rotors which are disclosed in Australian Patent 694679 (AU-B-62946/96) and International Patent Application PCT/AU00/01438 (WO 01/38697) which comprise a rotor which has a configuration which conforms generally to the curve of a logarithmic configuration substantially conforming to an equiangular spiral of the Golden Section which is also known as the Phi ratio. The contents of Australian patent 694679 and WO 01/38697 are incorporated herein by reference.
Rotors such as impellors, propellers turbine blades and fan blades have scarcely changed over the years and are relatively inefficient. In addition, it is a common characteristic of such fan blades that their use results in the generation of a considerable amount of noise and in turbulence. Furthermore, where rotors are used in a liquid environment, if the rotors are caused to rotate too fast, this can result in cavitation on the surface and tips of the rotor which not only reduces the operational efficiency of the rotor but can result in destructive influences on the rotor and the surrounding housing associated with the rotor. Typically, rotors force fluids into centrifugal moments, flinging the fluid to the extremities. This is used to advantage in centrifugal pumps, but also results in inefficiencies.
It is an object of this invention to provide a single or multi-bladed rotor which can react to or induce a fluid flow and whereby the usage of that rotor results in a reduction of the degree of extraneous turbulence and tip vortices exerted on the fluid in its passage past the rotor with the resultant energy loss and noise generation when compared to conventional rotors which are currently in use. Typically rotors according to the invention cause fluids to flow centripetally rather than centrifugally and subsequently are able to exploit associated efficiency.
Disclosure of the Invention
Accordingly, the invention resides in a rotor comprising a hub supporting a blade, the blade having an axial extent and extending transversely outwardly from the hub to define a first and second face of substantially corresponding configuration which conform to at least one logarithmic curve conforming to the Golden Section.
According to a preferred feature of the invention, the transverse cross sectional configuration of the faces is curved in conformity with the Golden Section.
According to a preferred feature of the invention, the extent of the blade which is transverse to the longitudinal axes varies along the length of the rotor accordance with a logarithmic curve conforming to the Golden Section.
According to a further preferred feature of the invention, fluid flow relative to the rotor is centripetal.
According to a preferred embodiment, the blade defines a helical vane having the configuration of a whorl.
According to a preferred embodiment, the blade has a shell-like configuration where the transverse displacement of the surfaces at an intermediate location along the length of the rotor is greater than the transverse displacement at either end.
According to a preferred feature of the invention, one end of the blade co-operates with the hub to define an open, generally axially directed opening, the other end being closed wherein the hub provides for fluid flow longitudinally through the rotor.
According to a embodiment, a single blade is mounted to the hub and the hub is provided with a counterweight positioned to balance the rotor in use.
According to a preferred feature of the invention at least two blades are mounted to the hub said blades being spaced angularly equidistant around the hub.
According to a preferred embodiment, the curvature of the faces are of substantially equivalent form.
According to a further preferred feature of the invention, the curvatures of the reactive surfaces are uni-dimensional. According to one embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially radial to the axis. According to another embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially tangential to the rotation path about said axis. According to another embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially coaxial with or substantially parallel with said axis.
According to a further preferred feature of the invention, the curvatures of the reactive faces are bi-dimensional. According to one embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially radial to the rotation path of that point about said axis and an axis which is substantially tangential to the rotation path about said axis. According to another embodiment the curvatures of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially radial to the axis and an axis which is substantially coaxial with or substantially parallel with said axis. According to another embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially tangential to the rotation path about said axis and an axis which is substantially coaxial with or substantially parallel with said axis.
According to a further preferred feature of the invention, the curvatures of the faces is three dimensional. According to one embodiment the curvature of the faces according to the logarithmic curve substantially conforming to the Golden Section is about an axis which is substantially radial to the rotation path, an axis which is substantially tangential to the rotation path about said axis and an axis which is substantially coaxial with or substantially parallel with said axis.
According a preferred feature of the invention, the rotor comprises a fan blade which is intended to induce or react to a gaseous flow past the rotor.
According to an alternative embodiment of the invention, the rotor comprises an aircraft propeller.
According to an alternative embodiment of the invention, the rotor comprises a watercraft propeller.
According to an alternative embodiment of the invention, the rotor comprises a marine jet pump impeller.
According to an alternative embodiment of the invention, the rotor comprises a pump rotor.
According to an alternative embodiment of the invention, the rotor comprises a turbine rotor.
According to an alternative embodiment of the invention, the rotor comprises a mixer rotor.
The invention will be more fully understood in the light of the following description of several specific embodiments.
Brief Description of the Drawings
The description is made with reference to the accompanying drawings of which : Figure 1 is an isometric view of a rotor according to the first embodiment; Figure 2 is a side elevation of the rotor according to the first embodiment; Figure 3 is a plan view of the rotor according to the first embodiment; Figure 4 is an inverted end view of the rotor according to the first embodiment as shown at Figure 3;
Figure 5 is a schematic isometric view of the first embodiment illustrating the fluid flow that it is believed is generated by the rotation of the rotor Detailed Description of Several Embodiments Each of the embodiments of the invention comprises a rotor having a hub supporting at least one blade. While embodiments having single blades are capable of operating satisfactorily, additional balancing would be required to enable satisfactory operation. it is envisaged that multi-bladed embodiments would generally be preferred to avoid the difficulties in balancing a single bladed rotor.
The rotors of the embodiments differ from prior art rotors by virtue of the blade or blades extending from the hub in an axial direction as well as extending transversely outwardly. Each blade defines a first and second surface of substantially corresponding configuration which conforms to at least one logarithmic curve conforming to the Golden Section.
The first embodiment shown in Figures 1 to 4 of the drawings comprises a rotor which has particular application as a propeller for a water craft. Alternatively, the rotor can be used as a fan, turbine, propeller, pump or mixer.
As shown at Figures 1 to 4, the rotor comprises a hub (112) which supports a set of two blades (111) extending both radially and axially from the hub. The hub (112) is formed with a central shaft or tube which is adapted to be mounted to a rotatable shaft or tube which comprises, in the case of a fan blade intended to induce fluid flow, a drive shaft driven from a suitable motor. Each of the blades are formed with an internal reactive face (114) which is of a concave configuration and which has a three dimensional curvature whereby the curvature in each dimension is about an axis which is radial to the central axis of the rotor, an axis which is tangential to the central axis of the rotor and an axis which is coincidental or parallel to the central axis of the rotor. In each case the curvature is in accordance with a logarithmic curve conforming to the Golden Section. As a result, the blades (111) jointly define a generally concave internal face of the rotor.
In addition, each blade has a remote reactive face (115) which is remote from the reactive face (114) and which also has a three dimensional curvature of a convex nature whereby the curvature in each dimension conforms with a logarithmic curve according to the Golden Section, and whereby the curvature in each dimension is of the same form as the curvature of the reactive face (114) in each dimension. As a result, the remote faces (115) jointly define a generally convex surface of the rotor.
As a result of this blade arrangement, the transverse displacement of the surfaces at an intermediated location along the length of the rotor is greater than the transverse displacement at either end.
It may be seen that the general appearance of the embodiment as shown at Figure 1 generally takes the form of pairs of shells of the phylum Mollusca, classes Gastropoda and Cephalopoda.
It has been found that the rotation of the rotor induces a fluid flow which is centripetal rather than centrifugal and subsequently are able to exploit associated efficiencies.
It is a particular characteristic which results from the configuration of the blades of the rotor as described above, that fluid flowing relative to the blades will be directed centripetally, that is inwardly towards the axis. This surprising effect which follows from the vortical motion of the fluid provides a number of advantages. In particular, it is found that when a rotor according to the embodiment is used as a propeller for a water craft, it is not necessary to use a shroud or the extent of shrouding required is significantly reduced.
The rotor according to the first embodiment is suitable for use in many applications such as pumping of liquids or gases, whereby with rotation of the rotor blade such that the one edge (116) forms the leading edge of each blade, fluid flow will be induced past the fan blade from the convex face to the concave face. Alternatively, the other edge (117) may form the leading edge for opposite rotation. Because of the curvature of the reactive face of each of the radial blades of the embodiment, the fan blade induces a vortical fluid flow in the fluid medium as it both approaches the rotor and as it exhausts from the rotor as illustrated at Figure 5.
It has been found that in use of the first embodiment the rotation of the rotor generates a fluid flow through the rotor in which the flowing fluid maintains its own inertia and if the rotor is stopped the fluid flow will continue through the rotor for a period of time because of such inertia. It is believed that this is at least in part due to the circumstance that the use of the rotor of the first embodiment results in the generation of a fluid flow in which the pathway for the fluid flow though the rotor (as distinct from conventional rotors) is constant in its geometry from a position in advance of the entry to the rotor to a position beyond the exit from the rotor.
The second embodiment shown in Figures 6 to 9 of the drawings comprises a rotor which also has application as a propeller for a water craft. Again it may also be used as a fan, pump, turbine, pond circulator or mixer.
As shown in the drawings, the rotor of the second embodiment has a very different appearance from that of the first embodiment. Nevertheless, the blades have a configuration which conform in most respects to the configuration described in relation to the first embodiment. To clarify the similarities, in identifying the features of the embodiment as shown in the drawings, like numerals are used to denote like parts.
The rotor of the second embodiment also comprises a hub (12) which supports a set of two blades (11) extending both radially and axially from the hub. The hub (12) is formed with a central shaft or tube which is adapted to be mounted to a rotatable shaft or tube which comprises, in the case of a fan blade intended to induce fluid flow, a drive shaft driven from a suitable motor. Each of the blades are formed with an internal reactive face (14) which is of a concave configuration and which has a three dimensional curvature whereby the curvature in each dimension is about an axis which is radial to the central axis of the rotor, an axis which is tangential to the central axis of the rotor and an axis which is coincidental or parallel to the central axis of the rotor. In each case the curvature is in accordance with a logarithmic curve conforming to the Golden Section. As a result, the blades (11) jointly define a generally concave intemal face of the rotor.
In addition, each blade has a remote reactive face (15) which is remote from the intemal reactive face (14) and which also has a three dimensional curvature of a convex nature whereby the curvature in each dimension conforms with a logarithmic curve according to the Golden Section, and whereby the curvature in each dimension is of the same form as the curvature of the reactive face (14) in each dimension. As a result, the remote faces (15) jointly define a generally convex surface of the rotor.
While these features are identical to those of the first embodiment, the blades of the second embodiment have the configuration of a whorl. It will be seen from the drawings that the blades provided a maximum diameter near to the hub but the diameter then diminishes further from the hub. Figure 10 illustrates the vortical flow induced by the rotor.
According to a third embodiment of the invention a rotor of a similar form to that of the first or second embodiment is used as the impeller of a fluid mixer, pond circulator or bioreactor.
According to a fourth embodiment of the invention a rotor of a similar form to that of the first or second embodiment is used as the impeller of a fluid pump.
According to a fifth embodiment of the invention a rotor of a similar form to that of the first or second embodiment is used as the impeller of a compressor.
According to a sixth embodiment of the invention a rotor of a similar form to that of the first or second embodiment is used as the turbine blade of a turbine.
It should be appreciated that the scope of the present invention need not be limited to the particular scope described above.
USD585130
Rotor
Rotor
FIG. 1 is a perspective view of the rotor, showing top and side views of the new design;
Throughout the specification, unless the context requires otherwise, the word "comprise"or variations such as"comprises"or"comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
Impeller
AU2011218759
AU2011218759
IL175217
FLUID CIRCULATION SYSTEM
IL177149
HOUSING FOR A CENTRIFUGAL FAN, PUMP OR TURBINE
WO2009051793
STRUCTURES
US2008265101
Vortex ring generator
Boat
USD577325
Axial flow fan
US2008145230
Rotor
USD570999
USD570999
Rotor
USD570996
Housing for a centrifugal fan, pump, or turbine
US2007003414
Vortical flow rotor
US2007025846
VORTICAL FLOW ROTOR
WO2005073560
Heat exchanger
ZA200405899
FLUID FLOW CONTROLLER.
MXPA04006591
Fluid flow control device
AU2004254279
SINGLE OR MULTIPLE BLADED ROTOR
WO03056139
HEAT EXCHANGER
AU2003201185
FLUID FLOW CONTROLLER
AU2003201183
SINGLE OR MULTIPLE BLADED ROTOR
AU2003201181