Propulsion Systems and Their Applications

Abstract

A propulsion system coupled to the rear of the hull of a waterborne transportation vehicle includes a convex surface, a pump configured to push a fluid, a diffusing structure coupled to the convex surface, at least one conduit coupled to the convex surface and configured to introduce a primary fluid provided by the pump to the convex surface, and a suction structure coupled to the convex surface and configured to introduce a secondary fluid accessible to the vehicle to the diffusing structure, wherein the diffusing structure has a terminal end configured to provide an outlet from the system for the introduced primary fluid and secondary fluid.

Description

Priority claim

[0001]

[0001] This patent application claims priority to U.S. Patent Application Serial No. 63 / 399,705, filed August 21, 2022, the entire contents of which are incorporated herein by reference as if fully set forth herein.

[0002] Copyright Notice

[0002] This disclosure is protected under United States and international copyright laws. © 2023 Jetoptera, Inc. All rights reserved. A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves any and all copyright rights whatsoever. [Background technology]

[0003]

[0003] In marine propulsion, a typical method is the use of a propeller driven by a motor. Propellers can range from large to small, and sometimes dual motors are used to propel the boat at slower speeds. The motor is usually an internal combustion engine or a gas turbine turboshaft. [Brief explanation of the drawings]

[0004] [Figure 1] FIG. 1 is a cross-sectional view of one embodiment of the present invention depicting only the top half of the ejector, showing the velocity and temperature profiles within the internal flow. [Figure 2]

[0005] FIG. 2 illustrates a cross-sectional portion of an ejector according to one embodiment. [Figure 3]

[0006] FIG. 3 illustrates a side perspective view of an ejector, according to one embodiment. [Figure 4]

[0007] FIG. 4 illustrates a top view of a boat hull not employing an embodiment of the present invention. [Figure 5]

[0008] FIG. 5 illustrates a top view of a boat hull employing an embodiment of the ejector. [Figure 6]

[0009] FIG. 6 illustrates a swimmer swimming in a recirculating swimming pool including one or more ejectors according to one embodiment. [Figure 7]

[0010] FIG. 7 illustrates a top view of the arrangement illustrated in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0005]

[0011] This application incorporates by reference U.S. Patent No. 10,207,812 and U.S. Patent Application Serial No. 15 / 685,975, as if fully set forth herein. An embodiment includes a propulsion system coupled to a vehicle. Such a system may include a diffusing structure and a conduit portion configured to introduce a primary fluid generated by the vehicle into the diffusing structure through a passageway. The passageway is defined by a wall, and the diffusing structure includes a termination configured to provide an outlet from the system for the introduced primary fluid. A constriction element is disposed adjacent to the wall. An actuator is coupled to the constriction element and configured to urge the constriction element toward the wall, thereby controlling the cross-sectional area of ​​the passageway. Water pumped to a higher pressure is injected at high velocity, generating thrust using a propulsion system submerged in water and offset from the vessel's hull to maximize water entrainment surrounding the vessel, creating a relatively unidirectional flow while moving the vessel in a direction opposite the water current. In one embodiment, the system can be integrated into the hull and deployed only when needed, as in the case of a sailboat. In another embodiment, the entire system can replace the outboard motor driving the propeller. The water pump can be electrically driven using batteries, generators, or hybrid turboshafts, or simple ICEs or gas turbines.

[0006]

[0012] In another embodiment, such motors and devices are used in swimming pools of limited size to generate a very stable, even velocity profile flow that a swimmer can swim against. The large volume of water mixed in creates a very uniform flow without the speed fluctuations that typically occur when using propellers and flow straighteners.

[0007]

[0013] Fewer, faster military vessels and jet skis utilize the water jet principle for propulsion.

[0008]

[0014] This propulsion method is highly efficient at the high speeds (over 30 knots) required by some applications, eliminates the noise generated by a propeller as it cuts through the water, and can also be used to steer the boat by directing the jet or for reverse by using a moving surface to deflect the flow backwards. Such an approach can also eliminate the cavitation effects that typically limit the operation and performance of a typical propeller.

[0009]

[0015] The amount of energy expended on board a boat to generate a unit of thrust and move the boat forward is a measure of the efficiency of the onboard propulsion system.

[0010]

[0016] The metric of "propulsive efficiency" is used in aviation and relates to the difference between the aircraft speed and the speed of the fluid (e.g., jet) leaving the aircraft. If these values ​​are close to each other, the efficiency is high but the thrust is reduced; conversely, if the jet speed is high and the aircraft speed is much smaller, the efficiency is low and, in fact, too much kinetic energy is not being used efficiently for propulsion reasons.

[0011]

[0017] Similarly, when a jet of incompressible fluid such as water is pushed at, say, 50 knots and the boat speed is, say, 45 knots, the efficiency is high. However, if the vessel is moving slowly (in port or generally, slower than, say, 20 knots) while the propulsion jet speed is high (say, 50 knots), the propulsion efficiency is low because more energy is utilized (more energy is wasted in the jet) without any immediate effect on the forward motion of the vehicle.

[0012]

[0018] Waterjets, used in various marine propulsion applications, eject a body of water previously pumped by a mechanical or electric pump at a speed greater than vehicle speed. Multiplying the jet's velocity by the mass flow rate yields the system's thrust. Embodiments provide a way to take the same amount of mass flow rate and, instead of directly ejecting it, utilize it as a primary ejection device to entrain and accelerate more water by, for example, tripling the total jet exiting the device and lowering the average velocity below that of the original jet, resulting in higher thrust for the boat when multiplied by the tripled mass flow rate. Conversely, the energy required to generate the original amount of thrust for the boat is reduced by the disclosed device, resulting in fuel savings. By placing the device in the boat's wake, streamlining of the flow around its hull is optimized, and the system can also yield savings from avoiding dead-water spots and stagnation of water in the wake. Integration of a water propulsion system with a hull according to one or more embodiments reduces its drag and streamlines the flow around the hull.

[0013]

[0019] In one embodiment, a water pump draws water from outside the vessel's hull, filters the water of any debris or vegetation, and directs the water flow to an impeller or other known water pumping means to increase the pressure to the value and flow rate required for the propulsion device.

[0014]

[0020] When deployed as a simple water jet without using embodiments of the present invention, the device increases the amount of water supplied to it and, thanks to its shape and structure, expels a mixture that increases the force generated by the primary jet of water. An advantage of embodiments is that it increases the thrust available from the jet alone by at least 1.5 times, and preferably by more than 2 times. This can be achieved, for example, by drawing in 4-5 parts water at a speed 3 times slower than the original jet. Since thrust is the product of the volume of water and the velocity of the water jet, using the present invention can result in a factor of, for example, 4 / 3 = 1.33 times greater thrust to 5 / 3 = 1.67 times greater thrust. Conversely, if a vessel requires a constant amount of thrust, a reduction in energy (or fuel) consumption of between 1 / 1.33 = 75% and 1 / 1.67 = 60% can be achieved. For higher speeds, the device can be bypassed and the original jet speed and flow can be used directly, while the device can be retracted into the hull to streamline the flow and reduce drag.

[0015]

[0021] In another embodiment, a water pump draws water from a large pool and pressurizes this flow into a main stream that feeds a similar device, in this case stationary, located at one end within the pool. The velocity profile exiting the device is more uniform or even than the use of a typical bladed rotor that generates a flow that is then diffused by the use of a straightening device, as in some products offered for swim training. The device can also be scaled in size or number, providing a much larger set of options for the swimmer (combinations of larger and smaller thrusters can be blocked or activated by a primary water flow fed through a system of multiple conduits).

[0016]

[0022] FIG. 1 illustrates a cross-sectional view of the upper half of an ejector 200 according to an embodiment of the present invention. The plenum 220 may be supplied with a fluid at a higher temperature than the ambient temperature. A pressurized motive fluid stream 600 communicates with the primary nozzle 203 via a conduit and enters the interior of the ejector. The primary nozzle accelerates the motive fluid 600 to the speed required by the ejector performance according to the design of the primary nozzle 203. The primary (motive) fluid 600 emerges at high speed as a wall jet over the Coanda surface 215, entraining an ambient fluid 1 that may be stationary or approaching the ejector from the left of the figure at a non-zero speed. The mixture of stream 600 and ambient fluid 1 moves purely axially in the throat section 225 of the ejector 200. Through diffusion in the diffuser 210, the mixing and smooth discharge process continues, and the temperature (750) and velocity profiles in the axial direction (700) no longer have the high and low values ​​present in the throat section 225, but are more uniform at the exit of the diffuser 210. As the mixture of 1 and 600 approaches the exit plane, the temperature and velocity profiles are nearly uniform.

[0017]

[0023] FIG. 2 illustrates, in cross section, and FIG. 3 illustrates, in a side perspective view, the ejector 200 illustrated in FIG. 1 , according to one embodiment. The ejector 200 includes a diffusing structure 210 and a conduit, such as a primary fluid region plenum 220. The plenum 220 supplies a primary fluid to the diffusing structure 210, and an intake structure 230 provides a secondary fluid, such as ambient air, to mix the primary and secondary fluids therein. The diffusing structure 210 includes a terminal end configured to provide an outlet from the ejector 200 for the mixed primary and secondary fluids. More specifically, in an embodiment, the plenum 220 introduces the primary fluid into the convex Coanda surface 215. As a non-limiting example, the primary fluid comprises pressurized water delivered to the plenum 220 via a primary fluid source, such as a duct 250. The ejector 200 further includes a flow controller 240.

[0018]

[0024] 4 illustrates a top view of a boat hull 400 that does not employ an embodiment of the ejector 200. The hull 400 is moving through the water, and streamlines 410 resulting from such movement are shown as creating dead water spots and stagnation of water in a wake area 420 behind the hull, thereby increasing drag forces acting on the hull.

[0019]

[0025] 5 illustrates a top view of a boat hull 500 employing an embodiment of the ejector 200. The hull 500 is shown moving through water, and streamlines 510 resulting from such movement are shown being streamlined by the ejector positioned in a wake area 520 aft of the hull, thereby reducing drag acting on the hull. The ejector 200 may be coupled to the hull 500 by struts 530 or other suitable coupling devices.

[0020]

[0026] Figure 6 illustrates a swimmer 600 swimming in a recirculating swimming pool 610 that includes one or more ejectors 200 using a water pump 630 that supplies water to one or more injectors via one or more ducts 250, for example. Flow streamlines 620 resulting from the operation of the ejectors 200 are shown as providing resistance to the swimmer 600, thereby causing the pool 610 to function as an "infinite swimming pool." Figure 7 illustrates a top view of the arrangement illustrated in Figure 6.

[0021]

[0027] While the above text provides detailed descriptions of many different embodiments, it should be understood that the scope of protection is defined by the language of the claims set forth below. The detailed description should be construed as merely exemplary and does not describe every possible embodiment, as doing so would be impractical, if not impossible. Many alternative embodiments could be implemented using either current technology or technology developed after the filing date of this patent and still fall within the scope of the claims.

[0022]

[0028] Thus, many modifications and variations can be made in the techniques and structures described and illustrated herein without departing from the spirit and scope of the claims. Accordingly, it should be understood that the methods and apparatus described herein are illustrative only and are not limiting on the scope of the claims.

Claims

1. 1. A propulsion system coupled to a rear portion of a hull of a waterborne vehicle, comprising: a convex surface; a pump configured to pump a liquid; a diffusing structure coupled to the convex surface; at least one conduit coupled to the convex surface and configured to introduce a primary fluid provided by the pump to the convex surface; and an intake structure coupled to the convex surface and configured to direct a secondary fluid accessible to the vehicle to a diffusing structure, wherein the diffusing structure has a terminal end configured to provide an outlet from the system for the introduced primary and secondary fluids.

2. A device that receives a flow or free stream of water at a pressure higher than that of the surrounding water in a tank, uses a shaped passage to take in several portions of the free stream or tank water for each high-pressure portion introduced, and discharges a substantially uniform flow of the mixed water source at a predetermined speed.

3. The device of claim 2 , wherein the predetermined speed is controlled by a pump throttle and a geometry that may be variable.

4. 10. A method of using the device of claim 2 to generate an equal force opposing said flow to propel a water vessel on the surface or underwater.

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