SLEEVE VALVE FOR A PULSED GAS GENERATOR

Abstract: The combination of a pulsed rocket engine 12 and a sleeve valve 10 coupled to the engine output and receiving in its internal chamber 16 the gas generated by the engine 12. The sleeve valve 10 has a movable sleeve 24 with ports 26, 28 therethrough surrounding the wall 18 of the chamber 16, the wall 18 having ports 38, 40 which axially align with the sleeve ports 26, 28 in the valve's open position to allow rapid dis­ charge of the contents of the chamber 16. The sleeve is ordi­ narily biased to a closed, or non-aligned, position for the ports by a spring 32. When the gas pressure in the chamber 16 reaches a predetermined amount, a pressure sensor 54 com­ mands a gas source to send pressurized gas into the valve 10 to force the sleeve 24 into its open position against the bias of the spring 32, thereby aligning the ports 26, 28 and 38, 40 and allowing rapid discharge of the gas from the sleeve-valve chamber 16.

Description: Background of the Invention 1. Field of the Invention This invention relates to a sleeve valve to be used in conjunction with a pulsed gas generator, especially a pulsed rocket engine for underwater acoustic applications. 2. Description of the Prior Art . It has been proposed that the pulsed rocket engine be utilized as an underwater sonic source. One version of this engine is described in U.S. Patent No. 4,258,546, issued March 31,1981 to H.S. Stratton. The engine can deliver a 3-10 msec pulse of exhaust gas at chosen pressure up to about 15,000 psi. However, it has been found that a pulse of pressure enduring for such a length of time tends to be absorbed by the large volume of water into which the pulse is delivered rather then to generate a usful acoustic wave, i.e., that the acoustic pressure wave does not attain as high an amplitude as it would with a shorter delivery time. It has been proposed too an underwater sound generator in U.S. Patent No. 4,098,369, from July 4,1978, having a valve to allow some of the high pressure P₁ gas to flow from the combustion chamber into the annular space next to the front face of the rim portion when opened. The resulting force is sufficient to overcome the opposing force urging the piston valve closed, whereupon the piston valve moves to the right. However, the flow of the pressure P₁ gas through the valve leads to a pressure reduction during that time in which a sonic pulse is to be generated. That means that the underwater sound generator known from citation has only a low sonic pulse generation efficiency. Object of the Invention It is an object of the present invention to provide for an apparatus for producing sonic pulses having its sonic pulse generation efficiency maximized. Summary of the Invention . The object and advantage of the present invention are achieved by that, that the movable means is a sleeve fitting around the outside of said chamber wall and having at least one port therethrough, said biasing means is a spring arranged between said sleeve and said chamber wall, a pressure sensor means is arranged within said internal chamber for sensing the gas pressure therein, and said gas source means is separate from the gas generator and coupled to receive the output signal of said pressure sensor means in order to move the sleeve so that the sleeve port aligns with the chamber-wall port when the internal chamber pressure produced by said gas generator reaches a predetermined level. That means that in order to solve the object of the present invention, the apparatur is so constructed, that a separate gas supply is provided for actuating the sleeve in response to an output signal from a pressure sensor arranged within the central chamber. This has the advantage that for actuating the sleeve no pressure gas from the central chamber is necessary. Therefore, a higher sonic pulse generation efficiency is obtained in contrast to the prior art. Brief Description of the Drawing . The single figure is an axial cross-section of a sleeve valve, in accordance with the invention, shown schematically connected to a pulse gas generator. Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing. Detailed Description of the Invention . The figure provides an axial cross-sectional view of a sleeve valve 10 and a schematic view of a pulsed rocket engine, used as the gas generator 12 to the output ent of which the valve 10 is coupled through a flange coupler 14. Gas is generated by this engine in repetitive pulses, generally about 10 msecs. in duration, at a variable rate of up to about 60 pps. The underwater frequency band of the pulser is about 25-250 Hz. The output thrust of the engine can be as much as 10,000 lbs. with a chamber pressure of up to 30,000 psia or more. The sleeve valve 10 is essentially tubular in construction, although it may have other shapes, such as rectangular, in the direction transverse to the longitudinal axis. A central chamber 16 is formed by a tubular chamber wall 18 and a chamber end plug 20 which closes off the end of the chamber 16. A bore 22 extends partially into the plug 20 from the downstream (with reference to the flow of gas from the gas generator 12) end. A sleeve 24 fits over the outside of the chamber wall 18. The sleeve 24 has a pair of opening ports 26, 28 in it and can be moved upstream as far as a shoulder 30 in the chamber wall 18. A spring 32 sits in a space 34 between the downstream side of the outside of the chamber wall 18 and a cylinder 36 which fits snugly over the outside of the chamber walls 18. The spring 32 exerts a downstream bias force on the sleeve 24 keeping the sleeve ports 26, 28 closed off from a pair of ports 38, 40 in the chamber wall 18. A tubular cap 42 is placed around the downstream end of the plug 20 and fastened to the end of the chamber wall 18 by means of bolts 44. The contact areas between the cap 42, the sleeve 24 , the chamber wall 18 and the plug 20 are sealed against flow of gas or outside fluid by means of a plurality of seals such as O-rings,seal rings, channel seals, etc., as shown by elements 46, 48 and 50. A channel 52 connects the actuation port 22 with the downstream end of the space between the cap 42 and the chamber wall 18, within which space the sleeve 24 slides. A pressure sensor 54 is placed in the chamber wall 16, although it may be places within the combustion chamber wall of the engine 12. The sensor 54 is electrically connected to control a gas source 56 which is separate from the gas generator and the output of which is fed into the actuation port 22 in the plug 20. In operation, the engine is fired and the gas output fills the chamber 16 of the sleeve valve 10. The pressure therein is sensed by the pressure sensor 54 and when the pressure reaches a preselected level (e.g.,6000 psia), a signal is sent to the gas source 56 commanding it to release gas into the actuation port 22. This gas has a pressure acting against the sleeve area to create a force sufficiently higher then the spring force to quickly move the sleeve 24 upstream to the chamber shoulder 30. This action also axially aligns the sleeve ports 26, 28 with the chamber-wall ports 38, 40, respectively, allowing the gas in the chamber 16 to suddenly discharge to the environment surrounding the sleeve valve 10. The fast-acting sleeve valve described herein, among other things: 1.) allows engine combustion to occur without the presense of water during initial pressure build-up, a factor that contributes to achieving high pressire from the engine combustion chamber, since the presence of water causes slow ignition by quenching the combustion process. 2.) eliminates the time required to build chamber pressure (rise time of the gas pulse) since the output pulse is released from the sleeve valve after the preselected pressure and volume is reached; and 3.)provides a rapid discharge of the predetermined gas volume at a desired pressure.

Claims: An apparatus for producing sonic pulses in an aqueous environment comprising: a gas generator (12) for producing gas, an essentially tubular means formed with a chamber wall (18) and an end plug (20) which define an internal chamber (16) being coupled to receive the output of said gas generator (12) , said chamber wall (18) having at least one port (38, 40) therethrough, a movable means (24) to be moved in longitudinal direction of the tubular means for closing or opening the port (38, 40), biasing means (32) urging the movable means (24) to shut off said port (38, 40), and a gas source means (56) for supplying pressured gas to the movable means (24) to move said movable means (24) against the force of said biasing means (32) in order to open said port (38, 40), characterized in that said movable means is a sleeve (24) fitting around the outside of said chamber wall (18) and having at least one port (26, 28) therethrough, said biasing means is a spring (32) arranged between said sleeve (24) and said chamber wall (18), a pressure sensor means (54) is arranged within said internal chamber (16) for sensing the gas pressure therein, and said gas source means (56) is separated from the gas generator and coupled to receive the output signal of said pressure sensor means (54) in order to move the sleeve (24) so that the sleeve port (26,28) aligns with the chamber-wall port (38, 40) when the internal chamber pressure produced by said gas generator (12) reaches a predetermined level. An apparatus as claimed in claim 1, characterized in that the plug (20) is formed with an actuating port (22) in its downstream end to receive gas from the gas source means (56) and with a channel (52) from the actuating port to a plug surface in contact with an actuating area of the sleeve (24). An apparatus as claimed in claims 1 or 2, characterized in that said gas generator (12) is a rocket-engine gas generator. An apparatus as claimed in claims 1, 2 or 3, characterized in that the gas generator (12) is pulsed.

Inventors: HILLMAN, JERRY L., KNAPP, JANET S.
Applicants: ROCKWELL INTERNATIONAL CORPORATION
Application year: 1986
Main classification: G01V1
IPC codes: F02K7, F15B21