Marine propulsor with inlet fluid inducer
Presented is a fluid propulsor for propelling a vehicle that incorporates a Coanda Effect Inducer (CEI), more commonly called an inlet fluid inducer in this application, in its inlet to induce fluids passing by the vehicle to turn uniformly toward a powered fluid energizing device such as a rotor of the propulsor. This concept enhances the efficiency of the rotor and the overall efficiency of the propulsor. The rotor is preferably at least primarily enclosed in a housing and the rotor may operate either fully submerged in liquid or in a partially liquid and partially gaseous environment. The CEI and the powered fluid energizing device are, in the preferred embodiment, installed in an inlet housing of the propulsor. Fluid flow directing devices may be incorporated to separate liquid from gas flowing to the rotor in some instances. The inlet fluid inducer may take the shape of a cylinder or any other flow directing shape and while more effective when rotating in the direction of fluid flow is also viable when not rotating.
This application is a continuation-in-part to applicant's earlier applications: Ser. No. 11/088,212 filed Mar. 18, 2005 now abandoned, Ser. No. 11/373,620 filed Mar. 10, 2006 now U.S. Pat. No. 7,422,498 issued Sep. 9, 2008, and Ser. No. 11/526,958 filed Sep. 26, 2006 now abandoned.
BACKGROUND OF THE INVENTIONEnclosed rotor propulsion system for marine craft, such as waterjets and Applicant's enclosed ventilated rotor Hydro Air Drive® (HAD) invention, are limited in the overall efficiency they can realize by the efficiency of recovery by their water inlets of the fluid available at their water inlets. As an example, waterjets can have very high efficiency rotors, stator vanes that straighten the discharge flow of the rotors, and discharge nozzles. The overall efficiency of the just mentioned three items are in the 90% or higher area for a well-designed high power level waterjet.
However, the overall efficiency of a waterjet is severely limited by its inlet's ability to recovery oncoming fluids efficiently. This is because the oncoming fluid flow is forced to turn into the duct that surrounds the waterjet's rotor. As an example, a waterjet's inlet may see efficiencies of fluid recovery of 92% over its lower half but only 54% or so over its upper half. This is because the fluid flow is separating over the upper part of the inlet duct as it is trying to turn from the inlet toward the rotor. This is so even though the waterjet operates as an enclosed pressurized system and thereby is creating suction at its inlet.
The HAD sees a slightly different situation in that it is not a pressurized system and therefore does not create much of a suction at its inlet. The advantage of the HAD is that it only operates with the lower half of its rotor submerged so its inlet fluid does not have to turn as far as does the waterjet's. However, the lack of inlet suction of the HAD does hamper the ability of its inlet to fully recover fluid approaching its inlet.
What all of this means is that propulsors, such as the waterjet and the HAD, would benefit greatly by having water inducer devices at their inlets. As a side point, it is realized that having a straight-in inlet with the inlet in-line with the rotor with no turns would provide high inlet efficiencies. Such an in-line inlet is sometimes referred to as a ram inlet. The shortcomings of the ram inlet are twofold—it: 1) has high drag due to the inlet's frontal area and 2) increases vessel draft since the ram inlet is normally lower than the vessel's keel. These shortcomings of the ram inlet are overcome by the instant-invention while maintaining the ram inlet's high efficiency.
The Coanda Effect can be used for turning fluids around curved surfaces and has been known for years. This Coanda Effect can be improved by use of a rotating cylinder or other curvilinear shape placed perpendicular to or at least partially perpendicular to the fluid flow to entice the fluid to turn in the direction of rotation of the rotating surface. The instant invention takes advantage of these known sciences and places a Coanda Effect Inducer (CEI) at or near the entrance of the receding inlet surface of a propulsor's inlet. The effect of the CEI is to greatly improve the recovery of fluids flowing past the propelled vehicle and of delivering such fluids to a fluid energizing device, such as a rotor, of the propulsor. This greatly improves the overall efficiency of the propulsor and hence the performance of the vehicle. Hereinafter, the CEI is commonly called an inlet fluid inducer.
What is called the receding inlet surface hereinafter is normally the upper surface in a standard waterjet propulsor installation. Such an upper receding inlet surface may be seen in Burg, U.S. Pat. No. 6,629,866, where, in that example, inlet flow directing valves 49, 51 act as the preceding mentioned receding inlet surface of the propulsor. Burg's flap-like flow directing valves 49, 51 are incapable of rotation through 360 degrees nor do his flap-like devices 49, 51 extend below the outlines of his hull which is the preferred embodiment of the instant invention especially when the instant invention's fluid inlet inducer 30 is fixed and not rotating. Propulsors installed in the sides of hulls, as presented in continuation-in-part Burg, U.S. Pat. No. 7,422,498, may see the receding inlet surface and its CEI more vertically oriented. In the instant invention the receding inlet surface may be oriented horizontally or at any angle to horizontal.
Willyard, U.S. Pat. No. 4,070,982, has a drive cylinder 16 disposed at the forward end or bow of a vessel 10 that energizes oncoming water. The energized water then flows completely through the length of the vessel 10 in a duct 15 to be discharged at the aft end of the vessel 10 thereby providing forward thrust. Portions of Willyard's energized water may be directed to a propeller 32 in a duct 31 positioned at the aft end or transom of his vessel 10. However, in no case does Willyard offer a CEI that is in powered communication with his propeller 32 except by the passing energized water. Further, Willyard does not offer a CEI that is housed in housings that also house the propelling rotor as does the instant invention. The instant invention, in its preferred embodiment, has its CEI integral with its rotor housing and/or an inlet housing attached to the rotor housing which is very important in order to simplify fabrication, installation, and maintenance. Further, Willyard has his drive cylinder 16 disposed at the water surface at the very bow of his vessel so that it sees oncoming waves and water mixed. This is contrary to the instant invention wherein the CEI is normally disposed at a further aft portion of the vessel's hull and normally sees only oncoming water.
A discussion of the instant invention and the advantages it offers is presented in detail in the following sections.
OBJECTS OF THE INVENTIONA primary object of the invention is provide an improved propulsor for propelling a vehicle where said propulsor accelerates fluid to produce thrust and where said fluid is obtained through an inlet that intakes fluid from external to the vehicle and directs said fluid toward a fluid energizing device wherein said inlet includes an inlet fluid inducer and wherein said inlet fluid inducer directs said fluid toward a fluid energizing device such as a powered rotor.
A related object of the invention is that the inlet fluid inducer may rotate.
A directly related object of the invention is that the inlet fluid inducer provide a uniformity to the energy in the fluid supplied to the fluid energizing device.
A related object of the invention is that said inlet fluid inducer be oriented more perpendicular to than parallel to a plane that includes a rotational axis of the fluid energizing device.
A further object of the invention is that the inlet fluid inducer be capable of rotation in the direction of fluid flow.
Yet another object of the invention is that the inlet fluid inducer extend less than 60 percent of its maximum dimension perpendicular to fluid flow beyond an average height of a vehicle hull portion when said vehicle hull portion is viewed proximal to, forward of, and in line with the inlet fluid inducer.
A directly related refining object of the invention is that said inlet fluid inducer extend less than 40 percent of its maximum dimension perpendicular to fluid flow beyond an average height of a vehicle hull portion when said vehicle hull portion is viewed proximal to, forward of, and in line with the inlet fluid inducer.
A further directly related refining object of the invention is that said inlet fluid inducer extend less than 20 percent of its maximum dimension perpendicular to fluid flow beyond an average height of a vehicle hull portion when said vehicle hull portion is viewed proximal to, forward of, and in line with the inlet fluid inducer.
Yet another object of the invention is that the inlet fluid inducer may rotate freely in the direction of fluid flow through 360 degrees of rotation with no powering means.
Another object of the invention is that the inlet fluid inducer may be driven by a power source that also drives the fluid energizing device through 360 degrees of rotation.
A directly related object of the invention is that a drive shaft of a fluid energizing device may also drive the inlet fluid inducer.
Still another object of the invention is that the fluid energizing device may receive primarily liquid over one portion of its rotation and primarily gas over another portion of its rotation.
A related object of the invention is that a fluid directing device may be disposed at least in its majority downstream of the inlet fluid inducer.
A directly related object of the invention is that the fluid directing device has the ability to, in at least one mode of its operation, restrict gas from passing to the fluid energizing device.
Another object of the invention is that the fluid directing device be powered by an actuator.
Yet another object of the invention is that the inlet fluid inducer may include recesses in its periphery that are capable of energizing fluids when the inlet fluid inducer is rotating.
A further object of the invention is that the inlet fluid inducer may be driven with gears.
Still another object of the invention is that the fluid energizing device be a rotor.
Yet another object of the invention is that the fluid discharge from the fluid energizing device may be given direction by a rudder.
A further object of the invention is that the inlet fluid energizing device by supported by an inlet housing of the marine propulsor.
Another object of the invention is that the inlet fluid inducer and the fluid energizing device be in mechanical communication in a common housing or a connected housing.
It is still another object of the invention that the inlet fluid inducer should be relatively close to the fluid energing device to maximize overall system efficiency.
A directly related object of the invention is that a distance from an aft portion of the fluid inlet inducer to a forward portion of the fluid energizing device be no more than six diameters of the fluid energizing device or rotor.
Another directly related object of the invention is that a distance from an aft portion of the fluid inlet inducer to a forward portion of the fluid energizing device be no more than four diameters of the fluid energizing device or rotor.
The inlet fluid inducer 30 should be relatively close to the fluid energing device or rotor 42 for maximum overall system efficiency. A distance from an aft portion of the fluid inlet inducer 30 to a forward portion of the fluid energizing device 42 of no more than six diameters of the fluid energizing device or rotor 42 is desired with values of less than four diameters preferred. Further, in this preferred embodiment of the instant invention, the inlet fluid inducer 30 is supported by the inlet housing 34. The two items presented in this paragraph are very important as they make for the best manufacture, installation, maintenance, and efficiency.
The dimension A given in
In
Each of these extensions, relative to the hull portions, have advantages and disadvantages. For example, in the case of a Surface Effect Ship (SES) such as applicant's SeaCoaster® that is supported by pressurized gas cushions with the propulsor inlets disposed at least primarily aft of the gas cushions it is best to have the inlet fluid inducer 30 extend beyond the hull portion in front of it as far as possible. This is because the gas cushions aerate the water and there may also be a layer of gas between the hull 39 and the water surface when it reaches the propulsor's water inlet. Having the inlet fluid inducer 30 extend outward beyond the hull means that its outward portions can work in relatively clean gas free liquid. Contrarily, it is desirable to have the inlet fluid inducer 30 not so far extended for a very high-speed craft.
Large displacement hulls may find extension of the inlet fluid inducer 30 to work best when at low values also. This is because of the boundary layer associated with large displacement hulls and the desire to take in water to the propulsor from close to the hull where it has already been brought up to near ship speed. The advantage of the instant invention in such a displacement hull application is that the propulsor gets an added thrust advantage from taking in the ship's accelerated boundary layer rather than quiescent water in outer reaches of the boundary layer. It is further to be noted that the instant invention may be disposed so that it is actually has all or part of its inlet higher than its fluid energizing rotor as would be the case when operating on the upper or side surfaces of hydrofoil, submarine, or other submerged or partially submerged vehicle.
Another item of note in
While the invention has been described in connection with a preferred and several alternative embodiments, it will be understood that there is no intention to thereby limit the invention. On the contrary, there is intended to be covered all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims, which are the sole definition of the invention.
Claims
1. In an improved propulsor for propelling a marine vehicle wherein said propulsor accelerates fluid to produce thrust and wherein said fluid is obtained through an inlet that intakes fluid from external to the marine vehicle and directs said fluid toward a powered fluid energizing device of said propulsor, the improvement comprising:
- an inlet fluid inducer wherein said inlet fluid inducer is capable of three hundred sixty degrees of rotation to thereby energize and direct said fluid toward the powered fluid energizing device and wherein a power source that supplies power to said powered fluid energizing device of said propulsor also supplies power to said inlet fluid inducer and wherein said inlet fluid inducer is driven by drive means in mechanical communication with a drive shaft of the powered fluid energizing device of said propulsor.
2. The improved propulsor of claim 1 wherein said drive means includes gears.
3. The improved propulsor of claim 1 wherein a distance from an aft portion of said inlet fluid inducer to a forward portion of the fluid energizing device is no more than six diameters of the fluid energizing device.
4. The improved propulsor of claim 1 wherein a distance from an aft portion of said inlet fluid inducer to a forward portion of the fluid energizing device is no more than four diameters of the fluid energizing device.
5. The improved propulsor of claim 1 wherein said inlet fluid inducer and the fluid energizing device are in mechanical communication by means of one or more housings of the propulsor.
6. The improved propulsor of claim 1 wherein said inlet fluid inducer extends less than 40 percent of its maximum dimension perpendicular to fluid flow beyond an average height of a vehicle hull portion when said vehicle hull portion is viewed proximal to, forward of, and in line with the inlet fluid inducer.
7. The improved propulsor of claim 1 wherein said powered fluid energizing device receives primarily liquid over one portion of its rotation and primarily gas over another portion of its rotation.
8. The improved propulsor of claim 7 wherein a fluid directing device is disposed, at least in its majority, downstream of the inlet fluid inducer and upstream of the fluid energizing device.
9. The improved propulsor of claim 1 wherein said inlet fluid inducer includes recesses in its periphery that are capable of energizing fluids when the inlet fluid inducer is rotating.
10. The improved propulsor of claim 1 wherein the inlet fluid inlet inducer is capable of free wheeling rotation in a direction of fluid flow when said inlet fluid inducer is not powered.
11. In an improved propulsor for propelling a marine vehicle wherein said propulsor accelerates fluid to produce thrust and wherein said fluid is obtained through an inlet that intakes the fluid from external to the marine vehicle and directs said fluid toward a powered fluid energizing device of said propulsor, the improvement comprising:
- an inlet fluid inducer wherein said inlet fluid inducer is capable of three hundred sixty degrees of rotation to thereby energize and direct said fluid toward the powered fluid energizing device and wherein a distance from an aft portion of said inlet fluid inducer to a forward portion of the fluid energizing device is no more than six diameters of the fluid energizing device.
12. The improved propulsor of claim 11 wherein a distance from an aft portion of said inlet fluid inducer to a forward portion of the fluid energizing device is no more than four diameters of the fluid energizing device.
13. The improved propulsor of claim 11 wherein said inlet fluid inducer and the fluid energizing device are in mechanical communication by means of one or more housings of the propulsor.
14. The improved propulsor of claim 11 wherein said inlet fluid inducer extends less than 40 percent of its of its maximum dimension perpendicular to fluid flow beyond an average height of a vehicle hull portion when said vehicle hull portion is viewed proximal to, forward of, and in line with the inlet fluid inducer.
15. The improved propulsor of claim 11 wherein said inlet fluid inducer is driven by drive means in mechanical communication with a drive shaft of the powered fluid energizing device of said propulsor.
16. The improved propulsor of claim 11 wherein said powered fluid energizing device receives primarily liquid over one portion of its rotation and primarily gas over another portion of its rotation.
17. The improved propulsor of claim 11 wherein a fluid directing device is disposed, at least in its majority, downstream of the inlet fluid inducer and upstream of the fluid energizing device.
18. The improved propulsor of claim 11 wherein said inlet fluid inducer includes recesses in its periphery that are capable of energizing fluids when the inlet fluid inducer is rotating.
19. The improved propulsor of claim 11 wherein the inlet fluid inlet inducer is capable of free wheeling rotation in a direction of fluid flow when said inlet fluid inducer is not powered.
20. The improved propulsor of claim 11 wherein a distance from an aft portion of said inlet fluid inducer to a forward portion of the fluid energizing device is no more than six diameters of the fluid energizing device.
21. The improved propulsor of claim 11 wherein a distance from an aft portion of said inlet fluid inducer to a forward portion of the fluid energizing device is no more than four diameters of the fluid energizing device.
22. In an improved propulsor for propelling a marine vehicle wherein said propulsor accelerates fluid to produce thrust and wherein said fluid is obtained through an inlet that intakes the fluid from external to the marine vehicle and directs said fluid toward a powered fluid energizing device of said propulsor, the improvement comprising:
- an inlet fluid inducer wherein said inlet fluid inducer is capable of three hundred sixty degrees of rotation to energize and direct said fluid toward the powered fluid energizing device and wherein said inlet fluid inducer and the fluid energizing device are in mechanical communication by means of one or more housings of the propulsor.
23. The improved propulsor of claim 22 wherein a distance from an aft portion of said inlet fluid inducer to a forward portion of the fluid energizing device is no more than six diameters of the fluid energizing device.
24. The improved propulsor of claim 22 wherein a distance from an aft portion of said inlet fluid inducer to a forward portion of the fluid energizing device is no more than four diameters of the fluid energizing device.
25. The improved propulsor of claim 22 wherein said inlet fluid inducer is driven by drive means in mechanical communication with a drive shaft of the powered fluid energizing device of said propulsor.
26. The improved propulsor of claim 22 wherein said fluid energizing device receives primarily liquid over one portion of its rotation and primarily gas over another portion of its rotation.
27. The improved propulsor of claim 22 wherein a fluid directing device is disposed at least in its majority downstream of the inlet fluid inducer.
Type: Application
Filed: Jan 16, 2009
Publication Date: May 21, 2009
Inventor: Donald E. Burg (Miami, FL)
Application Number: 12/321,357
International Classification: B63H 11/103 (20060101);