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 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. 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.
Enclosed 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% 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 creating a 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 recovery fluid approaching its inlet.
What all of this means is that propulsors, such as waterjet and the HAD, would benefit greatly from having some sort of water inducer device 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. The obvious problem with this is twofold, to wit: 1) Excessive drag due to high frontal area and 2) Very deep draft. Therefore the approach of an inline inlet is generally impractical.
The Coanda Effect can be used for turning fluids around curved surfaces and has been known for many 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), either rotating or not, at or near the entrance of the inlet of the propulsor. The effect of this 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. The CEI is commonly called an inlet fluid inducer herein.
A discussion of the instant invention and the advantages it offers is presented in detail in the following sections.
OBJECTS OF THE INVENTONA 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.
Another object of the invention is that the inlet fluid inducer be driven by a power source that also drives the fluid energizing device.
A directly related object of the invention is that a drive shaft of a fluid energizing device also drives 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.
An optional object of the invention is that the fluid discharge from the fluid energizing device may be given direction by a rudder.
BRIEF DESCRIPTION OF THE DRAWINGS
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 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, the improvement comprising:
- an inlet fluid inducer wherein said inlet fluid inducer is capable of rotation to direct said fluid toward the fluid energizing device and thereby provide a uniformity to the fluid supplied to the fluid energizing device and wherein said inlet fluid inducer is oriented more perpendicular than parallel to a plane that includes a rotational axis of the fluid energizing device.
2. The improved propulsor of claim 1 wherein the inlet fluid inducer rotates in the direction of fluid flow.
3. The improved propulsor of claim 1 wherein said inlet fluid inducer extends 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.
4. 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.
5. The improved propulsor of claim 1 wherein said inlet fluid inducer is driven by a power source that also drives the fluid energizing device.
6. The improved propulsor of claim 1 wherein said fluid energizing device receives primarily liquid over one portion of its rotation and primarily gas over another portion of its rotation.
7. The improved propulsor of claim 6 wherein a fluid directing device is disposed at least in its majority downstream of the inlet fluid inducer.
8. The improved propulsor of claim 7 wherein said fluid directing device has ability to, in at least one mode of its operation, restrict gas from passing to 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 fluid energizing device is a rotor.
11. In 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 the fluid from external to the vehicle and directs said fluid toward a fluid energizing device, the improvement comprising:
- an inlet fluid inducer wherein said inlet fluid inducer is capable of rotation to direct said fluid toward the fluid energizing device to thereby provide direction to the fluid supplied to the fluid energizing device and wherein the inlet fluid inducer rotates in the direction of fluid flow.
12. The improved propulsor of claim 11 wherein said inlet fluid inducer is oriented more perpendicular than parallel to a plane that includes a rotational axis of the fluid energizing device.
13. The improved propulsor of claim 11 wherein said inlet fluid inducer extends less than 60 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.
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 a power source that also drives the fluid energizing device.
16. The improved propulsor of claim 11 wherein said 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.
18. The improved propulsor of claim 17 wherein said fluid directing device has ability to, in at least one mode of its operation, restrict gas from passing to the fluid energizing device.
19. 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.
20. In 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 the fluid from external to the vehicle and directs said fluid toward a fluid energizing device, the improvement comprising:
- an inlet fluid inducer wherein said inlet fluid inducer is capable of rotation to direct said fluid toward the fluid energizing device and thereby provide uniformity to the fluid supplied to the fluid energizing device and wherein said inlet fluid inducer extends less than 60 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.
21. The improved propulsor of claim 20 wherein said inlet fluid inducer is oriented more perpendicular than parallel to a plane that includes a rotational axis of the fluid energizing device.
22. The improved propulsor of claim 20 wherein said inlet fluid inducer is driven by a power source that also drives the fluid energizing device.
23. The improved propulsor of claim 20 wherein said fluid energizing device receives primarily liquid over one portion of its rotation and primarily gas over another portion of its rotation.
24. The improved propulsor of claim 20 wherein a fluid directing device is disposed at least in its majority downstream of the inlet fluid inducer.
25. The improved propulsor of claim 24 wherein said fluid directing device has ability to, in at least one mode of its operation, restrict gas from passing to the fluid energizing device.
Type: Application
Filed: Mar 18, 2005
Publication Date: Oct 5, 2006
Inventor: Donald Burg (Miami, FL)
Application Number: 11/088,212
International Classification: B63H 11/00 (20060101);