WO2024044142A1

WO2024044142A1 - Propulsion system and applications thereof

Info

Publication number: WO2024044142A1
Application number: PCT/US2023/030731
Authority: WO
Inventors: Andrei Evulet
Original assignee: Jetoptera, Inc.
Priority date: 2022-08-21
Filing date: 2023-08-21
Publication date: 2024-02-29
Also published as: IL319090A; WO2024044142A9; EP4573005A1; CN119731078A; KR20250051677A; AU2023330901A1

Abstract

A propulsion system coupled to an aft portion of a hull of a water-borne vehicle includes a convex surface, a pump configured to impel a liquid, a diffusing structure coupled to the convex surface, at least one conduit coupled to the convex surface and configured to introduce to the convex surface a primary liquid provided by the pump, and an intake structure coupled to the convex surface and configured to introduce to the diffusing structure a secondary liquid accessible to the vehicle, wherein the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary liquid and secondary liquid.

Description

PROPULSION SYSTEM AND APPLICATIONS THEREOF

PRIORITY CLAIM

[0001] This application claims the benefit of U.S. Patent Application Serial No. 63/399,705 filed August 21, 2022, the entirety of which is hereby incorporated by reference as if fully set forth herein.

COPYRIGHT NOTICE

[0002] This disclosure is protected under United States and/or International Copyright Laws. © 2023 Jetoptera, Inc., All Rights Reserved. A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and/or Trademark Office patent file or records, but otherwise reserves all copyrights whatsoever.

BACKGROUND

[0003] In maritime propulsion the typical method is the use of propellers driven by a motor. The propellers vary from large to small, and sometimes dual motors are used for propelling a boat at lower speeds. Motors are usually internal combustion or gas turbines turboshafts.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0004] FIG. 1 is a cross-section of one embodiment of the present invention depicting only the upper half of an ejector and shows profiles of velocity and temperature within the internal flow;

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

[0006] FIG. 3 illustrates a side perspective view of an ejector according to an embodiment;

[0007] FIG. 4 illustrates a top view of a boat hull that does not employ an embodiment of the invention;

[0008] FIG. 5 illustrates a top view of a boat hull that does employ an embodiment of the ejector;

[0009] FIG. 6 illustrates a swimmer swimming in a recirculating swimming pool that includes one or more ejectors according to an embodiment; and

[00010] FIG. 7 illustrates a top view of the arrangement illustrated in FIG. 6.

DETAILED DESCRIPTION

[00011] This application incorporates by reference as if fully set forth herein U.S. Pat. No. 10,207,812 and U.S. Patent Application Serial No. 15/685,975. 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 produced by the vehicle to the diffusing structure through a passage. The passage is defined by a wall, and the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid. A constricting element is disposed adjacent the wall. An actuating apparatus is coupled to the constricting element and is configured to urge the constricting element toward the wall, thereby controlling the cross-sectional area of the passage. Water pumped to higher pressures is injected at high speeds, and with the propulsion system immersed into the water at an offset from the ship’s hull in a manner that maximizes the entrainment of the water surrounding the hull, produces a relatively unidirectional stream while producing thrust and moving the vessel in the direction opposite to the water flow. In one embodiment the system can be employed as integral to the ship’s hull and only deployed when needed, as for example, for a sailboat In another embodiment the entire system can replace an outboard motor that drives a propeller. The water pump can be driven electrically using a battery, a generator or a hybrid turboshaft, or a simple ICE or gas turbine.

[00012] In another embodiment, such motors and devices are used in a swimming pool of limited size, creating a very steady, equal velocity profile current that allows a swimmer to swim against it. The large amount of water entrained produces a very

uniform stream without the variations in speeds created usually when using a propeller and flow straightener.

[00013] Fewer, larger speed military vessels and jetskis utilize the principle of waterjets for propulsion.

[00014] This method of propulsion is very efficient at high speeds required by the application (exceeding 30 knots), eliminates noise made by the propeller when chopping the water and can be also used to steer the boat by vectoring the jets, or reverse by using moveable surfaces to deflect the flow backwards. Such an approach can also eliminate the cavitation effect that typically limits the operation and performance of a ty pical propeller.

[00015] The amount of energy spent on board of a boat to produce a unit of thrust and move the boat forward is a measure of efficiency of the propulsion system onboard.

[00016] The metric of “propulsive efficiency” is used in aviation, and it is related to the difference between the speed of the aircraft and the speed of the fluid (e.g., jet) leaving the aircraft. When they are close to each other in value, the efficiency is high, but the thrust is diminished; conversely, when the jet speed is high and the aircraft velocity is much smaller, the efficiency is low - in effect too much kinetic energy' is not being used efficiently for propulsive reasons.

[00017] Similarly, when a jet of incompressible fluid such as water is pushed at, e.g., 50 knots and the speed of the boat is, e.g., 45 knots, the efficiency is high. However, if the vessel is moving slowly (in harbors, or in general slower than, e.g., 20 knots,) while the speed of the propulsion jets is high (e g., 50 knots), the propulsive efficiency is small, as a higher energy is utilized without immediate effect on the vehicle movement forward (more energy' is wasted in the jet).

[00018] The water jets used in various applications for maritime propulsion eject, at higher than the vehicle speeds, a mass of water that was previously pumped by a mechanical or electric pump. The velocity of the jet multiplied by the mass flow rate gives the thrust of the system. An embodiment provides a way to take the same amount of mass flow rate and instead of ejecting it directly, to utilize it as primary ejector in order to entrain and accelerate more water for instance by tripling the total jet exiting the device and an average velocity lower than that of the original jet, however when multiplied by the triple the mass

flow rate, results in higher thrust for the boat. Conversely, the energy required to generate the original amount of the thrust for the boat is lowered with the disclosed device, resulting in fuel savings. By placing the device in the wake of the boat, the streamlining of the flow around its hull is optimized and the system may also incur savings from the avoidance of dead water spots and stagnation of w ater in the wake. Integration of the hull with the water propulsion system according to one or more embodiments will lower its drag and streamline the flow around the hull.

[00019] In one embodiment, a water pump pulls water from outside the hull of the vessel and filters the water of any debris or vegetation and directs the said water stream to an impeller or other known means of water pumping, raising the pressure to a value and flow rate needed for the propulsion device.

[00020] The device multiplies the amount of water supplied to it and ejects a mixture that, thanks to the shapes and architecture, multiplies the force produced by the primary jet of water were it to be deployed as a simple waterjet, without using an embodiment of the present invention. The benefit of an embodiment is the augmentation of the thrust otherwise obtained fromthejet alone by at least 1.5 times and preferably more than two times. This is achieved by, e.g., entrainment of 4-5 parts of water at three times lower speeds that the original jet; since thrust is the product of the amount of water times the velocity of the water jet, using this invention results in a factor of, e.g., 4/3 = 1.33 times more thrust to more than 5/3 = 1.67 times more thrust. Conversely, should the vessel require a fixed amount of thrust, a reduction of energy (or fuel) consumption to between 1/1 .33 = 75% to 1/1 .67 = 60% can be achieved. For larger 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, streamlining the flow and reducing drag.

[00021] In another embodiment, a water pump draws water from a large pool and pressurizes the stream to a main flow that supplies a similar device, this time stationary and placed inside the pool at one end. The profile of the velocity coming out of the device is more even or uniform than the use of the typical bladed rotors that generate a stream which is then spread out by use of a flow straightener, as in some of the products offered for swimming training. The device can be also scaled up or down by size or numbers, offering a much larger

set of options for the swimmer (larger and smaller combinations of thrusters can be shut off or on with primary water flow being supplied via a system of multiple conduits).

[00022] FIG. 1 illustrates a cross-section of only the upper half of an ejector 200 according to an embodiment. Plenum 220 may be supplied with hotter-than-ambient fluid. Pressurized motive fluid stream 600 communicates via conduits with primary nozzles 203 to the inner side of the ejector. The primary nozzles accelerate the motive fluid 600 to the speed required by the ejector performance, per design of the primary nozzles 203. The primary (motive) fluid 600 emerges at high speed over the Coanda surface 215 as a wall jet, entraining ambient fluid 1 which may be at rest or approaching the ejector at non-zero speed from the left of the figure. The mix of the stream 600 and the ambient fluid 1 are moving purely axially at the throat section 225 of the ejector. Through diffusion in the diffuser 210, the mixing and smoothing out process continues so the profiles of temperature (750) and velocity in the axial direction (700) have no longer high and low values as they do at the throat section 225 but become more uniform at the exit of the ejector. As the mixture of 1 and 600 approaches the exit plane, the temperature and velocity profiles are almost uniform.

[00023] FIG. 2 illustrates in cross-section, and FIG. 3 illustrates in side perspective view, the ej ector 200 according to an embodiment and illustrated in FIG. 1. Ej ector 200 includes a diffusing structure 210 and a conduit portion, such as primary fluid area plenum 220. Plenum 220 supplies primary fluid, and an intake structure 230 provides secondary fluid, such as ambient fluid, to the diffusing structure 210 for mixing of the primary and secondary fluids therein. The diffusing structure 210 comprises a terminal end configured to provide egress from the ejector 200 for the mixed primary and secondary fluids. More particularly, and in an embodiment, plenum 220 introduces the primary⁷ fluid to a convex Coanda surface 215. The primary fluid may consist of, for non-limiting example, pressurized water delivered to plenum 220 via a primary-fluid source, such as a duct 250. Ejector 200 further includes a flow controller 240.

[00024] FIG. 4 illustrates a top view of a boat hull 400 that does not employ an embodiment of the ejector 200. Hull 400 is moving in water and flow streamlines 410 resulting

from such movement are shown as forming dead-water spots and stagnation of water in the wake area 420 aft of the hull thereby increasing drag forces acting on the hull.

[00025] FIG. 5 illustrates a top view of a boat hull 500 that does employ an embodiment of the ej ector 200. Hull 500 is moving in water and flow streamlines 510 resulting from such movement are shown as being streamlined by ejector being positioned in the wake area 520 aft of the hull thereby decreasing drag forces acting on the hull. Ejector 200 may be coupled to hull 500 by a strut 530 or other appropriate coupling device.

[00026] FIG. 6 illustrates a swimmer 600 swimming in a recirculating swimming pool 610 that includes one or more ejectors 200 employing a water pump 630 that provides water to the one or more injectors via, for example, one or more of ducts 250. Flow streamlines 620 resulting from operation of ejector(s) 200 are shown as providing resistance to the swimmer 600 thereby causing pool 610 to function as an “endless swimming pool.” FIG. 7 illustrates a top view of the arrangement illustrated in FIG. 6.

[00027] Although the foregoing text sets forth a detailed description of numerous different embodiments, it should be understood that the scope of protection is defined by the words of the claims to follow. The detailed description is to be constmed as exemplary only and does not describe every possible embodiment because describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims.

[00028] Thus, many modifications and variations may be made in the techniques and structures described and illustrated herein without departing from the spirit and scope of the present claims. Accordingly, it should be understood that the methods and apparatus described herein are illustrative only and are not limiting upon the scope of the claims.

Claims

What is claimed is:

1. A propulsion system coupled to an aft portion of a hull of a water-borne vehicle, the system comprising: a convex surface; a pump configured to impel a liquid; a diffusing structure coupled to the convex surface; at least one conduit coupled to the convex surface and configured to introduce to the convex surface a primary liquid provided by the pump; and an intake structure coupled to the convex surface and configured to introduce to the diffusing structure a secondary liquid accessible to the vehicle, wherein the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary liquid and secondary liquid.

2. A device that receives a water flow rate at higher pressure than the ambient water in a tank or free stream and uses a shaped path to entrain several parts of free stream or tank water for each high-pressure part introduced and expels a nearly uniform stream of the mixed water sources at prescribed speed.

3. The device of claim 2 where the prescribed speed is controlled by the pump throttle and geometry which may be variable.

4. A method of using the device of claim 2 to generate an equivalent force opposite to the stream to propel a water vessel on surface or submerged.