US3472193A

US3472193A - Captive air bubble air replenishment process

Info

Publication number: US3472193A
Application number: US708214A
Authority: US
Inventors: Henry J Bernaerts
Original assignee: HENRY J BERNAERTS
Current assignee: HENRY J BERNAERTS
Priority date: 1968-02-26
Filing date: 1968-02-26
Publication date: 1969-10-14
Anticipated expiration: 1986-10-14

Description

oct. 14, 1969 H- J4 BERNJERTS 3,472,193

CAPTIVE AIR BUBBLE AIR REPLENISHMENT PROCESS Filed Feb. 26, 1968 ATTORNEY! United States Patent O 3,472,193 CAPTIVE AIR BUBBLE AIR REPLENISHMENT v PROCESS Henry J. Bernaerts, 900 Primrose Road, Apt. 203, Annapolis, Md. 21403 Filed Feb. 26, 1968, Ser. No. 708,214 Int. Cl. B631) 1/38 U.S. Cl. 114-67 10 Claims ABSTRACT OF THE DISCLOSURE A surface effect vehicle having side skirts or walls such as captured air bubble vehicle or the like is provided with submerged, movable vehicle propelling thrusters located forwardly of the bubble so that their exhausts may be directed to portions of the vehicle to enhance the side wall seal and to replenish air in the bubble.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

Background and summary In higher sea states a surface effect vehicle such as a captured air bubble vehicle tends to lose its air sealing at its side walls or skegs. Wave activity exposes the bottom extremities of the skegs past which air may escape. The purpose of this invention is to provide an arrangement whereby there is related to the vehicle configuration vehicle-propelling streams of water which may have gas entrained therein. These vehicle-propelling streams are produced by thrusters and are directed toward the vehicle side walls and/or toward the forward portion of the air cushion. In this arrangement the stream of water enhances the bubble seal and provides air for replenishing the bubble by employing wake effects of the advantageously positioned thrusters.

Brief `description of the drawings For a better understanding of the invention, reference is made to the accompanying drawings in which like numerals represent like parts and in which:

FIGS. 1 and 2 are respective side elevation and plan views of vehicle/propulsion arrangement according to one version of the invention, and

FIG. 3 is a view in side elevation for further describing the invention and its operation.

Detailed description and operation Referring to FIGS. 1 and 2, a surface effect vehicle illustrated as a captured air bubble vehicle 11 of configuration similar to that shown in U.S. Patent No. 3,- 146,752 issued to A. G. Ford, has respective fore and aft end walls or

curtains

13 and 15, port and starboard side walls or

skegs

17 and 19, and a captured air bubble 21. Two water states and levels are represented at relatively low sea states by solid line 23 and at higher sea States by broken line 25 in relation to the vehicle 11.

At the forward end of vehicle 11 is a vehicle body portion 27 extending forwardly of the curtain 13. Extending downwardly, forwardly and outwardly from body portion 27 are respective port and starboard faired

struts

29 and 31 of rigid construction and firmly attached in any suitable well known manner to the vehicle 11. The exact point of attachment of the struts is not critical as long as their lowerniost extensions are forward of the curtain 13 and outboard of the skegs. Preferably, the lowermost extensions are below the bottom surfaces of the skegs.

3,472,193 Patented Oct. 14, 1969 ice Each of the

struts

29, 31 may be of hollow, framed construction covered by any suitable strong skin material. At the bottom of the respective struts are respective rotatably mounted thrusters or

propulsion units

33, 35. The

thruster units

33, 35 may be identical and may be of any suitable design configuration capable of producing a water stream with or without gas entrained therein. For example, the thrusters may be high speed propellers, Kort nozzles, pump jets or, preferably, water ramjets of the type known commercially as Marjets manufactured by the Martin Marietta Co. Marjets are well known in the art and are not discussed in detail. Essentially, a Marjet is an axial flow ramjet having aperture means for introducing into the iiow air or gas at high pressure to produce a high velocity exhaust of water entrained air.

As shown in FIGS. 1-3, the

propulsion units

33, 35 are one or more thrusters mounted at the bottom of each strut for rotation about an axis parallel to the intersection line of the transverse plane and the longitudinal plane of symmetry of the vehicle. Fluid such as air at high pressure may be introduced to each thruster via conduits 37, 39, respectively, in the struts.

A source of high pressure fluid, such as gas or air, is indicated at 41, it being understood that such source may be of any suitable well known design, e.g., axial or centrifugal compressor, rocket, air-ramjet, and the like. A valve control switch 43 may be provided for the source 41 in order to selectively supply air or gas to the thrusters. Of cou-rse, because the thrusters 33, 365 are rotatable, a rotary seal coupling each of the conduits 37, 39 to the respective thrusters may be employed. Such seal may be of any suitable Well known design.

Any suitable well known means, not shown, may be employed to steer or rotate the respective thrusters. For example, hydraulically actuated and controlled pistons may rotate a gear coupled to the thruster; or a worm gear rotated by electrical or pneumatic motors may be coupled to a gear means rotating each thruster.

In operation, as best shown in FIGS. 2 and 3, when each thruster is in a position A parallel to the fore-aft axis of the vehicle, the propulsion efficiency for the vehicle is at a maximum. Further, because of the wake effect of each thruster, there is advantageously present a wave effect acting on the outer surfaces of

skegs

17 and 19 against the wave producing action of the skegs themselves. This action tends to provide greater amounts of water of high kinetic energy for providing `a seal at the vicinity of the skeg bottoms than would otherwise be the case. The high kinetic energy water stream tends to break down the preexisting wave amplitudes at the skeg surfaces so that wave pattern 25 is reduced to a pattern 23.

When

rotatable thrusters

33, 35 are in their B positions, as indicated in FIG. 2, additional volumes of water are directed against the outer surfaces of the skegs. In the B position, the thrust eiciency of the thrusters is decreased somewhat in favor of producing additional thrusted exhaust water and air entrained therein which provides at the outer surfaces of the skegs water ow which diminishes the elfect of ambient wave action to a degree greater than when the thrusters are in position A. As shown in FIG. 3, ambient waves 25 are diminished in amplitude at the vicinity of the outer surfaces of the skegs so as to form lower amplitude waves 23.

When the thrusters are at position C, thruster exhaust is directed towards the forward curtain 13. Because the thruster exhaust may contain both water and air entrained therein, the air supply of the cushion 21 is replenished. Mode C is particularly advantageous for providing bubble stability at high sea states.

Obviously, thruster positions intermediate A', B, and C, may be selected so that the individual effects of these positions are combined. For example, assuming the thrusters produce air entrained water streams, a thruster position between A and B provides slightly less propulsion efficiency and greater water supply at the outer surfaces of the skegs than at position A. A thruster position intermediate B and C provides a predetermined ratio of effects between that of position B and the air replenishment mode of position C.

It is to be understood that while the version of the invention has been described in relation to a captured air bubble type of vehicle, the principles of the invention apply to any surface effect vehicle employing side skirts, i.e., hydroskimmers, Hovercraft, and the like.

While the version of the invention shown is directed toward positioning thrusters outboard of the skegs, it is realized that advantages similar to those already described herein are obtained by placement of the thrusters at positions forward of the curtain 13 and inboard of the skegs. With inboard placement of the

thrusters

33, 35, the supply of air in the cushion will be replenished in all directional modes of the thrusters, while boundary condition control at the junction of skegs and water will occur in conjunction with air replenishment when the thrusters are turned outwardly from direct fore and aft alignment.

Each of the

thrusters

33, 35 may comprise a pump producing a high kinetic energy water stream without appreciable entrained gas to carry out the objectives of the A and B modes. Alternatively, each of the thrusters may comprise means to produce air entrained water streams of high kinetic energy to accomplish the objectives of all three modes, A, B and C. If desired, each thruster may comprise means such as control 43 to produce selectively a water stream with or without entrained gas or air. For example, an axial ow water pump may have valve controlled air injecting means whereby air may be selectively injected into the water flow downstream of the pump compressor.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. The method of controlling the effects of varying sea states on a surface effect vehicle having a supporting air cushion at least partially confined by water surface piercing, longitudinal side walls comprising the step of:

directing a vehicle-propelling stream of water against the forward portion of a surface of at least one of said side walls to enhance the seal between said air cushion and said side walls.

2. The method of controlling the effects of varying sea states on a surface effect vehicle having a supporting air cushion at least partially confined by water surface piercing, longitudinal side walls comprising the step of:

directing a vehicle-propelling stream of water having gas entrained therein toward the forward portion of the air cushion to replenish the air in said air cushion.

3. The method of controlling the effects of varying sea states on a surface effect vehicle having a supporting air cushion at least partially confined by water surface piercing, longitudinal side walls comprising the step of:

directing a vehicle-propelling stream of water having gas entrained therein both against the forward portion of a surface of at least one of said side walls to enhance the seal between said air cushion and said side walls and toward the forward portion of the air cushion to replenish the air in said air cushion.

4. For a surface effect vehicle having at least two water surface piercing, longitudinal side walls at least partially confining a vehicle-supporting cushion of air, means for propelling the vehicle and for enhancing the seal between the air cushion and the side walls, said means comprising:

submerged vehicle-propelling thruster means located essentially forwardly of the submerged body outline of said vehicle, said thruster means producing output propulsion products including a water stream of high kinetic energy; and

strut means for attaching said thruster means to said vehicle whereby the output of the thruster means is adapted to be directed aftwardly and in a direction against at least a portion of the plan outline of the vehicle.

5. Apparatus according to claim 4 wherein said thruster means comprises a port and a starboard thruster element.

6. Apparatus according to claim 5 wherein said strut means comprises a respective strut member for each said thruster element.

7. Apparatus according to claim 5 wherein each of said thruster elements is mounted for rotation about an axis essentially parallel to the intersectional line of the transverse plane and the longitudinal plane of symmetry of the vehicle.

8. Apparatus according to claim 5 wherein each of said thruster elements is positioned outboard of the side walls of the vehicle.

9. Apparatus according to claim 4 including means for supplying gas under pressure to said thruster means, whereby the output propulsion products of said thruster means include gas entrained therein to thereby enable replenishment of the air cushion.

10. For a surface effect vehicle having at least two water surface piercing, longitudinal side walls at least partially confining a vehicle-supporting cushion of air, means for propelling the vehicle, for enhancing the sealing of the air cushion, and for replenishing the air in said air cushion, said means comprising:

a port and a starboard vehicle-propelling thruster essentially submerged, each thruster being located essentially forwardly of the submerged body outline of the vehicle;

strut means attaching each thruster to said vehicle, each of said thrusters being rotatably mounted on said strut means;

a source of gas for each of said thrusters; and

means connectively associated with said source of gas for selectively supplying said gas to said thrusters whereby the thrusters produce Water streams with or Without gas entrained therein.

References Cited FOREIGN PATENTS 19,451 6/1904 Austria. 1,129,834 5/1962 Germany.

ANDREW H. FARRELL, Primary Examiner