Abstract:
A propulsion system may include a cylindrical support member and a tubular rotatable member rotatably mounted within the support member that may be adapted to permit fluid flow therethrough. The tubular rotatable member may extend past a down stream end of the support member. An exemplary embodiment of a propulsion system may also disclose a vane attached on an interior surface of the tubular member and may include a blade which extends in a direction toward a rotational axis of the rotatable member such that rotation of the tubular member and the vane attached thereon draws fluid into the tubular member to accelerate the fluid flow through the tubular member. Additionally, a nozzle may be attached to the down stream end of the support member and include a primary nozzle and a secondary nozzle within the primary nozzle. The secondary nozzle may be engaged with the primary nozzle by a stator.

Description:
This application claims priority under 35 U.S.C. 119 (e) of U.S. Provisional Application Ser. No. 60/996,895, filed Dec. 10, 2007, the entire contents of which are hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     In conventional propulsion systems, propellers perform the work required to accelerate fluid molecules to a desired velocity, but the propellers are unable to operate further on the fluid molecules to follow up on the work that was expended to overcome the initial inertia. This is due to the fact that a fluid molecule at rest tends to remain at rest and thus once placed in motion, a relatively smaller amount of energy is required to further accelerate it. Additionally, parts in conventional propulsion systems are easily damaged by foreign objects and unprotected screw-type propulsion systems pose a danger to divers and other living systems which pass in the vicinity of the propulsion system. 
     Those skilled in the art relating to propulsion systems have found that the propulsion efficiency of a propeller may be increased by carefully channeling the fluid flow to a propeller and similarly directing the accelerated fluid flow efficiently as it leaves the back of the propeller. In the past, various types of conical enclosures or nozzles have been fashioned in an attempt to increase the performance of propellers. 
     Essentially, a conical enclosure or nozzle surrounds the propeller in a longitudinal direction and directs fluid flow exiting from the propeller blades. The principles of fluid dynamics dictate that the volume of water flowing into the propeller will equal the volume of water flowing out. As such, the diameter of the nozzle is reduced as the water flows rearward and out of the nozzle. Since the volume of water exiting must equal the volume that enters the nozzle, the water flow accelerates as it travels through the nozzle and thereby provides additional thrust which cannot be achieved by the propeller alone. 
     SUMMARY 
     An exemplary embodiment of a propulsion system may disclose a cylindrical support member and a tubular rotatable member rotatably mounted within the support member that may be adapted to permit fluid flow there through. The tubular rotatable member may extend past a down stream end of the support member. An exemplary embodiment of a propulsion system may also disclose a vane attached on an interior surface of the tubular member and may include a blade which extends in a direction toward a rotational axis of the rotatable member such that rotation of the tubular member and the vane attached thereon draws fluid into the tubular member to accelerate the fluid flow through the tubular member. Additionally, a nozzle may be attached to the down stream end of the support member and include a primary nozzle and a secondary nozzle within the primary nozzle. The secondary nozzle may be engaged with the primary nozzle by a stator. 
     Another exemplary embodiment can disclose a propulsion system which may include a nozzle attached to a down stream end of a support member. The nozzle may include a primary nozzle and a secondary nozzle within the primary nozzle. The secondary nozzle may be engaged with the primary nozzle by a stator. The primary nozzle may define first, second and third sections extending along a longitudinal direction of the primary nozzle. The first section may extend in a direction that is substantially parallel to a central longitudinal axis of the nozzle, the second section may taper inwardly in a direction toward the central longitudinal axis and the third section may extend in a direction that is substantially parallel to the central longitudinal axis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Advantages of embodiments of the propulsion system will be apparent from the following detailed description of the exemplary embodiments thereof, which description should be considered in conjunction with the accompanying drawings in which like numerals indicate like elements, in which: 
         FIG. 1  is an exemplary cross-sectional longitudinal view of an exemplary embodiment of a propulsion system. 
         FIG. 2  is an exemplary side view of an exemplary embodiment of a nozzle of a propulsion system. 
         FIG. 3  is another exemplary side view of an exemplary embodiment of a nozzle of a propulsion system. 
         FIG. 4   a  is an exemplary downstream view of an exemplary embodiment of a nozzle of a propulsion system in an unengaged position. 
         FIG. 4   b  is an exemplary downstream view of an exemplary embodiment of a nozzle of a propulsion system in a fully engaged position. 
         FIG. 5  is an exemplary side view of an exemplary embodiment of a propulsion system. 
     
    
    
     DETAILED DESCRIPTION 
     Aspects of the propulsion system are disclosed in the following description and related drawings directed to specific embodiments of the propulsion system. Alternate embodiments may be devised without departing from the spirit or the scope of propulsion system. Additionally, well-known elements of exemplary embodiments of the propulsion system will not be described in detail or will be omitted so as not to obscure the relevant details of the propulsion system. Further, to facilitate an understanding of the description, discussion of several terms used herein follows. 
     The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Likewise, the terms “embodiments of the propulsion system,” or “exemplary embodiments,” do not require that all embodiments of the propulsion system include the discussed feature, advantage or mode of operation. 
     Other examples of the below-described exemplary embodiments may be used or adapted to be used with U.S. Pat. No. 5,383,802 which is hereby incorporated by reference in its entirety. 
     In an exemplary embodiment, as shown in  FIG. 1 , a propulsion system  100  may include an outer shell  102  having bearings  106  for supporting a rotor  104 . Outer shell  102  may provide bearing support for rotor  104  and further provide ducting and streamlining for rotor  104 . Rotor  104  may be hollow with vanes  108  extending from an interior surface of rotor  104  in the direction of the rotational axis of rotor  104 . Rotor  104  may define first, second and third sections which may extend along a longitudinal direction of rotor  104 . The first section of rotor  104 , as seen in  FIG. 1  beginning at the furthest up-stream location (the left-side as seen in  FIG. 1 ), may be slightly tapered to provide a venturi effect so as to draw air into a fluid medium passing through rotor  104 . In an exemplary embodiment where the first section inwardly tapers, the second section may begin at a point along rotor  104  where further restriction by the tapering first section would inhibit the fluid flow, however, the point at which the second section begins may not be limited to this point and may depend on design considerations. The second section may extend outwardly to a third section which may gradually return to a surface which may be parallel to the axis of rotation of rotor  104  at the exit of rotor  104 , at a down-stream location. 
     Vanes  108  may extend from rotor  104  and the vane shapes when viewed in cross-section from a point perpendicular to the rotor&#39;s rotational axis may define an archimedes screw, but may change in angle of attack and loaded surface areas in proportions that roughly correspond to fluid speed and rotor diameter. The number of blade sections may depend on design considerations and can be less than or more than three. 
     The propulsion system may enhance efficiency due to air inducted into the fluid by natural venturi effects or vapor formed in areas of low pressure. The design may draw air and vapor into areas of low pressure that would normally allow vapor bubbles to form and collapse. In addition, energy lost due to turbulence at apices and trailing edges of vanes  108  may be decreased by dropping or holding a stream of entrained air and vapor in close proximity to (or impinging upon) areas of predicted low pressures. The rotor wall constriction in the first section rotor  104  may indirectly compress air and vapor admitted to high stress areas, effectively pre-loading higher-pressure air, gas or vapor into these regions. Consequently, potential regions of vapor formation and accumulation may be filled with gas, vapor, or air pockets. In typical operation, a low pressure area implies the expansion of gas or air to fill the anticipated vacuum, and, because low pressure phenomena may occur with steadily increasing frequency throughout the rear two thirds of the propulsion device, vapor tends to accumulate into even larger, stable, visible gas or air pockets suspended between the fast-moving outer ring of fluid that may be driven by vanes  108  and the slower moving inner core of fluid that may form around the axis of rotation of rotor  104  in the center area that may not be disturbed by vanes  108  due to increased pressure caused by flow constriction within the nozzle. This gaseous region may remain largely contained within the secondary nozzle  114 . 
     In another exemplary embodiment, propulsion system  100  may utilize water lubricated bearings  106  and drive systems that may require cooling or heat removal/transfer systems. A gap  116  between the end of rotor  104  and a primary nozzle  112  may be adapted to provide a means of escape for high pressure water from the interior of rotor  104 . This high pressure water may be directed through gap  116  into the space surrounding bearings  106  and could potentially surround components of a drive system or any other desired structure or components housed between outer shell  102  and rotor  104 . This may provide a positive pressurized flow between moving and static surfaces. Gap  116  may vary in size for example, 0.25 inches, or any other desired gap size. Additionally, gap  116  may be expanded to release additional pressurized water or other desired fluid for use in cooling, for example, electric drives, internal combustion engines, or any other desired system requiring pressurized fluid. 
     In another exemplary embodiment, as seen in  FIG. 1 , ducts  110  may be formed in the side walls of rotor  104  at high and low pressure sides of vanes  108 . Ducts  110  may introduce high pressure water to water-lubricated bearing interfaces. The high pressure water may enter ducts  110  on the high pressure side of vanes  108 , cool and lubricate bearings  106  and then be reintroduced at the low pressure side of vanes  108  which may result in a closed loop cooling and lubrication system with substantially no volumetric loss of fluid passing through rotor  104 . The pressure differential between the two openings of ducts  110  may provide a current of pressurized fluid, such as water, to any desired location outside of rotor  104 . Ducts  110  may also be diverted to other desired tasks or locations which may result in a corresponding reduction of fluid pressure in the interior of rotor  104 . The positioning of ducts  110  can be in any desired location through the walls of rotor  104  and be of any desired shape or size. 
     A further exemplary embodiment of a propulsion system  100 , as seen in  FIGS. 1-5 , may include a primary nozzle  112 , a secondary nozzle  114  and at least one stator  118 , but may include any desired number of stators  118 . Secondary nozzle  114  may be affixed within primary nozzle  112  by stators  118 . 
     Primary nozzle  112  may be placed at a point of largest diameter of the interior of rotor  104  and may be mounted to outer shell  102 , at a down-stream side, through welding or any other type of fastening mechanism that may provide a fluid tight seal between outer shell  102  and primary nozzle  112 . The interface created by the attachment of primary nozzle  112  and outer shell  102  may approximate a continuous static interior surface with vanes  108  extending from rotor  104 . 
     Down-stream from the attachment of primary nozzle  112  and outer shell  102 , the interior of primary nozzle  112  may reduce in diameter which may induce a constriction or reduced cross-sectional area. The reduction in diameter of primary nozzle  112  may vary according to desired vectoring of the fluid flow through primary nozzle  112  and the desired increase in flow acceleration, for example, the angle of curvature of the primary nozzle  112  and secondary nozzle  114  may be between 15 and 30 degrees or any other desired angle of curvature. The constriction caused by primary nozzle  112  may induce acceleration in fluid flow and an increase in pressure on the fluid from the point of exiting the rotor  104  to the terminating downstream end of primary nozzle  112 . 
     Secondary nozzle  114  may be positioned approximately at the apices of the inner edges of the furthest downstream vanes  108  and may also reduce in diameter at a rate of curvature equal or different than the rate of curvature of primary nozzle  112 . The inner walls of secondary nozzle  114  may generally follow the contours or the outer walls of secondary nozzle  114  and may be configured to reduce flow disruption between the up stream side of the primary nozzle  112  and secondary nozzle  114  and the down stream side of the primary nozzle  112  and secondary nozzle  114 . At least one stator  118 , but may be as many as desired, may be mounted between the inner surface of primary nozzle  112  and the outer surface of secondary nozzle  114 . Stator  118  may be used to maintain the spatial and static separation between primary nozzle  112  and secondary nozzle  114 . 
     The separation between primary nozzle  112  and secondary nozzle  114  may provide a channel which may facilitate a physical separation between inner and outer streams of fluid. In operation, as rotor  104  rotates, fluid may be forced through rotor  104  and into primary nozzle  112  and secondary nozzle  114 . As rotor  104  rotates the fluid, for example water, may be separated into a liquid outer stream and a vapor inner stream. The outer liquid stream may be naturally forced outward against the inner walls of primary nozzle  112 . Secondary nozzle  114  may be configured, as seen in  FIG. 1 , to allow gaseous expansion from rotor  104  and vanes  108  at the upstream side and then facilitate acceleration of the vapor and gas by the reduction in diameter of secondary nozzle  114  at the downstream side. Thus the channel between primary nozzle  112  and secondary nozzle  114  may facilitate the flow of the liquid portion of the fluid flow and secondary nozzle  114  may facilitate the flow of the vapor portion of the fluid flow. 
     Stators  118  may impinge on fluid flow exiting rotor  104  and direct fluid flow downstream of primary nozzle  112  and secondary nozzle  114 . Stators  118  may be mounted at locations immediately downstream from vanes  108  and may be formed at the upstream side with an angle of attack that may approximate the angle of vanes  118  at the downstream side of rotor  104 . Stators  118  may gradually decrease in angle of attack, eventually aligning in parallel with the axis of rotation of rotor  104  and the longitudinal axis of primary nozzle  112 . This formation of stators  118  may aid in altering the velocity vector of the exiting fluid, forcing the fluid to exit the primary  112  and secondary nozzles  114  to exit parallel to the axis of rotation of rotor  104 , in such a way that may increase the potential and actual thrust of the overall propulsion system  100 . 
     The separation of the vapor and liquid flow by primary nozzle  112  and secondary nozzle  114  may attribute to an increased thrust of rotor  104 . Adding primary nozzle  112  and secondary nozzle  114  to rotor  104  may produce a 400 percent increase in thrust when compared to the thrust of rotor  104  alone. This increase in thrust may also be attributed to the containment of radially centrifuged high pressure liquid and the separation and pressurization of internally generated vapor flow. The percent increase in thrust may increase or decrease depending on, for example, the rate of curvature of primary nozzle  112  and secondary nozzle  114 . 
     In another exemplary embodiment, as seen in  FIGS. 2-5 , primary nozzle  112  may include steering ports  201  and braking ports  207 , each of which creates an opening through the wall of primary nozzle  112 . Each steering port  201  may be coupled with a corresponding steering port flap  200 . Steering ports  201  may be located at any desired position on primary nozzle  112  and, for example, may be located on the first 20 percent of the upstream side of primary nozzle  112 . Additionally, steering ports  201  and corresponding steering port flaps  200  may, for example, be symmetrically or asymmetrically oriented around the periphery of primary nozzle and may be formed in any desirable shape or configuration. Steering ports  201  and corresponding steering port flaps  200  may also be located on the first 20% of the upstream portion of primary nozzle  112 , the first half of the upstream portion of the primary nozzle  112  or at any other desired location over the entire length of primary nozzle  112 . 
     Steering port flaps  200  may be formed to seal steering ports  201  when placed in a closed position. Steering port flaps  200  may have a hinge  202  or be otherwise attached at an upstream position with respect to primary nozzle  112 , as can be seen in  FIG. 2 . The number of steering ports  201  and corresponding steering port flaps  200  may range from a single steering port  201  and corresponding steering port flap  200  to as many as desired. 
     In another exemplary embodiment, as seen in  FIGS. 4   a - 5 , hinges  202  may facilitate opening steering port flaps  200  in such a way that fluid flow may exit primary nozzle  112  at an angle that may be less than or equal to 90 degrees from the direction of the downstream exit of primary nozzle  112 . Steering port flaps  200  may be incrementally opened, thus diverting select amounts of fluid flow from the inside of primary nozzle  112  through steering ports  201 . As fluid flow is diverted through selected steering ports  201 , the diverted flow may alter the velocity vector of the overall fluid exiting primary nozzle  112 , thus providing a means of adjusting the direction of the thrust of nozzle  112 . 
     In a further exemplary embodiment, as seen in  FIG. 3 , each braking port  207  may be coupled with a corresponding braking port flap  206 . Braking ports  207  may be located at any desired position on primary nozzle  112  and, for example, may be located on the first 20 percent of the up stream side of primary nozzle  112 . Additionally, braking ports  207  and corresponding braking port flaps  206  may, for example, be symmetrically oriented around the periphery of primary nozzle and may be formed in any desired shape or configuration. Braking ports  207  and corresponding braking port flaps  206  may also be located on the first 20% of the upstream portion of primary nozzle  112 , the first half of the upstream portion of the primary nozzle  112  or at any other desired location over the entire length of primary nozzle  112 . 
     Braking port flaps  206  may be formed to seal braking ports  207  when placed in a closed position. Braking port flaps  206  may have a hinge  208  or be otherwise attached at a downstream position with respect to primary nozzle  112 , as can be seen in  FIG. 3 . The number of braking ports  207  and corresponding braking port flaps  206  may range from a single braking port  207  and corresponding braking port flap  206  to as many as desired. 
     In a further exemplary embodiment, as seen in  FIGS. 4   a - 5 , hinges  208  may facilitate opening braking port flaps  206  in such a way that an upstream portion of braking flap  206  may be opened externally to primary nozzle  112  and a downstream portion may extend internally into primary nozzle  112 . The downstream portion of braking flap  206  may act as a partial valve, restricting a portion of fluid flow from exiting primary nozzle  112  between secondary nozzle  114  and primary nozzle  112 . The upstream portion of braking port flap  206  may open from an upstream side of braking port  207  and may force a portion of the fluid flow from primary nozzle  112  to be diverted out of primary nozzle  112  at an angle that may be between 90 and 180 degrees from the direction of the downstream exit of primary nozzle  112 . Braking port flaps  206  may be incrementally opened, thus diverting a select amount of fluid flow from the inside of primary nozzle  112  through braking ports  207 . 
     As fluid flow is diverted through selected braking ports  207 , the diverted flow may be directed in a generally opposite direction of the overall fluid exiting primary nozzle  112 , thus reducing the velocity vector of the overall fluid exiting primary nozzle  112 , and acting as a braking mechanism for propulsion system  100 , during use. Additionally, the upstream portion of braking port flap  206  may act as a drag on propulsion system  100  when opened. The amount of drag created by the braking port flap  206  may be directly correlated to the amount braking port flap  206  is opened and may add to the braking ability of propulsion system  100 . 
     In another exemplary embodiment, steering port flaps  200  and braking port flaps  206  may be utilized in directional control of propulsion system  100 , as seen in  FIGS. 2-5 . Any combination of opening and closing steering port flaps  200  may divert fluid flow and thrust away from the downstream side of primary nozzle  112  at different variable angles, which may be used to facilitate steering or adjusting the trim of the propulsion system  100 . Any combination of opening and closing braking port flaps  206  may divert fluid flow in an opposite direction from the fluid flow exiting the downstream side of secondary nozzle  114 , thus reducing or breaking the thrust vector of the fluid flow exiting the downstream side of secondary nozzle  114 . This braking system may, therefore, not necessitate closing off the downstream side of either the primary nozzle  112  or the secondary nozzle  114 . Hard or extreme steering may, for example, require a combination of opening and closing specific steering port flaps  200  and braking port flaps  206 . 
     In a further exemplary embodiment, opening and closing steering port flaps  200  and braking port flaps  206  may be accomplished by a mechanical release mechanism. For example, rod  204  may mate with a groove on steering flap  200 , as seen in  FIG. 2 , and may be retracted in the direction of hinge  202  as a means of releasing steering flap  200  and allowing fluid flow from within nozzle  112  to escape through steering port  201 . This rod  104  and groove mechanism may be used to incrementally control the opening and closing of both steering port flaps  200  and braking port flaps  206 . Hinges  202  and  208  may also be spring loaded or otherwise biased toward an open or closed position as an additional means of facilitating the opening of both steering port flaps  200  and braking port flaps  206 . 
     Additionally, for example, opening and closing steering port flaps  200  and braking port flaps  206  may be accomplished via magnetic servos, control wires, piezoelectric mechanisms or any other mechanical, electrical or magnetic devices capable of incrementally opening and closing both steering port flaps  200  and braking port flaps  206 . Control systems may also be employed to communicate with and control the opening and closing devices, mentioned previously, in order to open or close steering port flaps  200  and braking port flaps  206  from a remote location. 
     The foregoing description and accompanying drawings illustrate the principles, preferred embodiments and modes of operation of the invention. However, the permit application and issuance system should not be construed as being limited to the particular embodiments discussed above. Additional variations of the embodiments discussed above will be appreciated by those skilled in the art. 
     Therefore, the above-described embodiments should be regarded as illustrative rather than restrictive. Accordingly, it should be appreciated that variations to those embodiments can be made by those skilled in the art without departing from the scope of the permit application and issuance system as defined by the following claims.