US3044253A

US3044253A - Method and apparatus for jet propulsion through water

Info

Publication number: US3044253A
Application number: US726334A
Authority: US
Inventors: Zwicky Fritz
Original assignee: Aerojet General Corp
Current assignee: Aerojet Rocketdyne Inc
Priority date: 1947-02-04
Filing date: 1947-02-04
Publication date: 1962-07-17
Anticipated expiration: 1979-07-17

Description

F. zwlcKY 3,044,253

.llull W, 1962 METHOD AND APPARATUS FOR JET PROPULSION THROUGH WATER 5 Sheets-Sheet 1 Filed Feb. 4, 1947 INVENTOR. FRITZ Z W/CK Y July W, 11962 zw 3,044,253

METHOD AND APPARATUS FOR JET PROPULSION THROUGH WATER 5 Sheets-Sheet 2 Filed Feb". 4, 1947 INVENTOR.

1 7 FRITZ zw/c/rr AT TOR/V5 Y5 Jully W, 1962 F ZWICKY METHOD AND APPARATUS FOR JET PROPULSION THROUGH WATER Filed Feb. 4, 1947 s sheet-sheet 3 INVENTOR.

FRITZ ZW/C/(Y BY m ATTORNEYS July 17, 1962 F. ZWICK Y 3,044,253

METHOD AND APPARATUS FOR JET PROPULSION THROUGH WATER Filed Feb. 4, 1947 5 Sheets-Sheet 4 IN V EN TOR.

FRI 72 Z W/CK Y A T TORNEYS July 17, 1962 F. ZWICKY 3,044,253

METHOD AND APPARATUS FOR JET PROPULSION THROUGH WATER Filed F 1947 5 Sheets-Sheet 5 V 96 98 3,61L #54752 42 6| 50 WATER FUEL) I 54 /05 93 Jae/r PUMP 1 A, "1 Z 45 43 7 Ii '1 47 9/ I HUI I]! a W I] m ll l4 l5 I/ E m g 3 g l r E 5 i t mzu. 1; mm TEMPERATURE A TTOl-P/VEYS United States Patent 3,044,253 METHOD AND APPARATUS FDR JET PROPULSTQN THRGUGI-I WATER Fritz Zwicky, Pasadena, Qaliil, assignor, by mesne assignments, to Aerojet-General Corporation, Cincinnati,

Ohio, a corporation of flhio Fiied Feb. 4, 1947, Ser. No. 726,334 20 tilaims. (Cl. 60-355) This invention relates to jet propulsion, and more particularly to the jet propulsion of devices through a water medium.

The principal object of the invention is to provide a method and means of operating a jet propelled device through water with high efliciency and impulse and without excessive overheating.

In my co-pending application Serial Number 661,485, filed April 12, 1946, now abandoned, I have disclosed and claimed the reaction of light metals with water for the purpose of producing high specific impulse jets for developing thrust. The use of such propellants for producing thrust has the desirable features that it does not involve detonable, corrosive, or toxic materials. Furthermore, no ignition device is required and excessively high reaction chamber temperatures are avoided. A further advantage of the use of such propellants is that they possess high density impulse. By density impulse I mean the product of the average specific gravity of the substance multiplied by the specific impulse.

My present invention is based upon my discovery that the speed of reaction between water and the light metals or light metal compounds or alloys can be increased by first melting the light metal substance and then subjecting the molten material to a degree of heating above its melting point before bringing it into contact with the water.

I have found, furthermore, that these metals are characterized by a very marked increase in the rate of spontaneous reaction at a critical degree of heating above the melting point. The phenomenon is quite marked, as I have found that by increasing the temperature of these light metals up to the melting point, there will usually be only a slight increase in their rate of reaction with the water. But upon increasing the temperature somewhat further, up to the critical temperature somewhat above the melting point, the reaction rate suddenly increases to the much greater rate.

I make use of the light metal propellant materials for jet propulsion through a water medium by the provision of means for superheating the light metal or light metal compounds or alloy propellant to the desired temperature above its melting point; and then bringing this superheated propellant material into contact with the water of the medium within the device to produce spontaneous reaction or decomposition.

A motor or unit suitable for the purpose may comprise a fluid channel or duct having an inlet opening and an exhaust opening or nozzle and a reaction chamber or region within the duct between the inlet and outlet ends. A suitable valve placed between the inlet opening and the reaction chamber will serve to admit the water and to enable the pressure to be built up in the reaction chamber.

A feature of my invention is the provision of an auxiliary reaction chamber in correlation with the main reaction chamber, the auxiliary chamber being provided with means for heating the propellant material and discharging it at a proper rate into the main reaction chamber.

A related feature is the provision of means associated with the auxiliary reaction chamber for initially heating the propellant material before allowing it to be injected into the main reaction chamber for the spontaneous reaction with the water.

Patented July 1'7, 1962 The foregoing and other features of my invention will be better understood from the following detailed description and the accompanying drawings of which:

FIG. 1 is a longitudinal plan view showing the assembled motor:

FIG. 2 is a front elevation of the motor of FIG. 1;

FIG. 3 is an enlarged cross section view showing the injector assembly and auxiliary reaction chamber;

FIG. 4 is a cross section on the line 4-4 of FIG. 3 showing the lower portion of the injector and the auxiliary heating chamber rotated from the view shown in FIG. 3 and showing the main injection orifices.

PEG. 5 is an end plan view of the auxiliary reaction chamber showing the auxiliary jet orifices with the auxiliary nozzle removed;

FIG. 6 is a perspective view of one of the valve blades;

FIG. 7 is a broken perspective view taken from above showing the manner in which the valve blades cover the channels;

FIG. 8 is an end plan view partly in cross section showing a valve blade interleaved between two valve channels;

FIG. 9 is a cross section view of the valve assembly taken on the line 9-9 of FIG. 1;

FIG. 10 is a diagrammatic view of the assembled motor; and

FIG. 11 is a graphical representation of the effect of temperature on the reaction rate of propellant materials.

The jet motor shown in the drawings comprises a duct 10 having an inlet opening or mouth 9 and an exhaust opening or nozzle 15. Within the inlet opening there is located a valve assembly 12; and between the valve and the exhaust opening there is a reaction chamber 11.

The reaction chamber 11 begins at the rear of a valve assembly 12 and its forward end conforms with the out line of valve housing 12a which in this case is rectangular. The reaction chamber 11 then undergoes a transition from the rectangular to a circular shape as it progresses downstream. The rear end of the reaction chamber is provided with a coupling member 14 to which is attached the exhaust nozzle 15. An opening 16 is provided in a wall of the reaction chamber 11 which permits insertion of an injector or auxiliary reaction chamber unit 13.

The auxiliary reaction chamber unit 13 comprises a body member 20 which houses a pintle controlled flow regulator and an auxiliary reaction chamber 18. The portion of body member 20 which houses the flow regulator is outside the reaction chamber 11, and the portion which houses the auxiliary reaction chamber is located inside the reaction chamber 11. An auxiliary jet orifice 19 is attached to auxiliary reaction chamber 18.

The injector and auxiliary reaction chamber member is constructed as follows: The portion of the body member 20 which extends outside the reaction chamber is preferably cylindrical in shape and is made substantially larger in diameter than the opening 16 which is made in the walls of the reaction chamber 11. The diameter of that portion of the cylindrical body member 20 which is placed inside the reaction chamber is reduced so that it fits within the opening 16 in the reaction chamber wall. A reduction in diameter forms an annular shoulder 21 which rests against a boss 22, which is attached securely around the opening 16. The diameter of the portion of body member 20 which is inside the reaction chamber is continued at the reduced diameter up to end 23. A spiral groove 24 is provided in the outer surface of reduced portion of body member 20 starting at a point located a substantial ditsance below shoulder 21 and continuing to within a short distance of end 23. This forms a spiral partition 25 which has the same outer diameter as the reduced portion of cylindrical body 20. A radial hole 40, perpendicular to the axis of the body 20 is drilled from the top uppermost channel to a point slightly beyond the center of body 20.

An axial hole 28 is provided in the reduced portion of body member 20 starting at end 23 and continuing to a point approaching approximately the start of the second turn of the spiral groove 24. A series of fins 29 starts 'from the circumference of hole 28 and continues to within a short distance of the inner wall of the spiral conduit 24. Fins 29 extend from the upper end of axial hole 28 and continue to within a short distance of end 23 of the body member 20. These fins are preferably uniformly spaced over the entire circumference of hole 28 as shown in FIGS. 4 and 5. The area formed by the axial hole 28 including the space between fins 29 constitutes the auxiliary reaction chamber 18.

The diameter of axial hole 28 is increased for a short distance from end 23 until it conforms with the largest diameter of the circle for-med by the bottom of the fins 29. Threads 30 are provided on this increased diameter.

1 An annular sleeve 26 is provided to slide snugly over the outer circumference of spiral partition 25. The outer diameter of sleeve 26 corresponds to the diameter of opening 16 and the opening in boss 22 and its inner diameter is proportioned to fit snugly over the end of the spiral partitions 25. Sleeve 26 extends from the annular shoulder 21 to the lower end 23 of body member 20 and when in this position closes spiral groove 24 to form a spiral channel. Leakage from the spiral channel past the ends of sleeve 26 is prevented by providing a pair of

annular grooves

31 and 32 located just above and below the ends of spiral groove 24. rings 33 and 34 are seated inside of annular grooves 31 aind 32 making the sleeve leakproof. That portion of sleeve 26, which corresponds to the last three turns of spiral groove 24, is provided with 'a plurality of orifices 35 positioned so as to be centered with respect to the upper and lower walls of the channel which they face, and are located at uniform intervals around the circumference of the sleeve. These orifices are drilled at varying angles with respect to the body member 20* to permit injections of streams of liquid at varying angles, for example, the upper groove orifices would form an angle less than 90, with the central axis, pointing toward the top of the reaction chamher, the central ones would be perpendicular to the central axis of the body 20 and the lower ones would form an angle greater than 90 with the central axis of body member 20 as has been indicated in FIG. 4.

A cup-shaped member 17 provided with threads to engage threads 30 and having substantially the same outside diameter as that of sleeve 26 is threaded on until it presses against sleeve 26 and the lower end 23 of the reduced portion of body member 20. The cup-shaped member 17 is provided with a nozzle 19 preferably of the De Laval type, which when the unit is installed in the jet motor has its axis pointing toward the exhaust end of the duct 15. The gases fromthe reaction chamber 18 collect in cup-shaped recess 17 and then escape through nozzle 19 into the main reaction chamber 11.

' The portion of body member 20 which is outside of the reaction chamber is provided with an axial bore 36 which extends into the cylindrical body a substantial distance from end 3-7. The diameter of bore 36 is then reduced and continued at a lesser diameter to within a short distance of the upper edge of radial hole 40 forming a cylindrical space 38. At this point the diameter of the bore is greatly reduced to form a connecting channel 39 which opens into conduit 40, thus connecting the cylindrical area 38 with the uppermost turn'of spiral groove 24.

An orifice 41, smaller in diameter than connecting channel 38, is drilled on the axis of the body member 20 and connects the upper end of auxiliary reaction chamber 18 with radial hole 40.

Bore 36 is provided with an annular recess 42 which is positioned a substantial distance from the end '37 of 4 body member 20. The portion of bore 36 above annular recess 42 is counter bored to a slightly larger diameter 36a.

A threaded bore 43 is provided which is preferably perpendicular to the axis of body member 20 and is positioned so that it can be connected to annular recess 42 by a smaller channel 44.

A second threaded bore 45, also perpendicular to the axis of body member 20 and preferably in the same longitudinal plane passing through the axis of threaded bore 43 is provided in the cylindrical body 20 below bore 43. Bore 45 is positioned so that a short conduit 46', smaller in diameter than bore 45, will connect it with the lower end of bore 36. v A third threaded bore 47 drilled on the same longi tudinal plane as

bores

43 and 45 and positioned below bore 45 is provided near the lower end of the enlarged portion of body member 20. This bore is connected to the reduced bore 38 by means of a connecting channel 48.

A fourth threaded bore 49, preferably located on the same longitudinal plane as bores 43, '45 and 47 is positioned near the upper end 37 of cylindrical body 20 and is connected 'to the upper end of the cylindrical space formed by axial bore 36a by a connecting passage 50.

A hole 51 perpendicular to the axis of body member 20 is preferably located on the same longitudinal plane as that described by the axis of

holes

43, 45, 47 and 49 but placed on the opposite side of the axis of cylindrical body 20 from

bores

43, 45, 47 and 49. Hole 51 is continued until it intersects central bore 36. The upper end of this bore is positioned so that it will intersect bore 36 a short distance below the lower edge of annular recess 42.

A hole 52 lying in substantially the same longitudinal plane as described by the axis of

bores

43, 45, 47 and 49, but on the same side as transverse hole 51 is drilled from the upper end 37 of cylindrical body 20 and is continued to within a short distance {of upper end of auxiliary reaction chamber 18. This hole connects to the .upper end of the auxiliary reaction chamber 18 by means of an orifice 53 of smaller diameter drilled from the side of the reduced portion of body member 20 at an angle such that it will intersect the axis of orifice 41 at a point within reaction chamber 18.

Bore 52 is shown in the illustration FIG. 3 to be drilled at an angle to the axis of cylindrical body 20. This is done to permit orifice 53 to be positioned more suitably with respect to orifice 41. The outer end of bore 51 and the upper end of bore 52 are then plugged to, prevent leakage. This may be done either by a threaded plug, welding, or other suitable means. The flow of liquid from bore 47 into the lower portion of bore 38 is regulated by a pintle 54. Pintle 54 comprises a piston-shaped portion 55, which conforms with the diameter of bore 36, a bearing section 56 which is smaller in diameter than piston-shaped portion 55 and corresponds with the diameter of bore 38, and a closure portion 57 which is smaller in diameter than bearing por tion 56. The end of closure section 57 is ground to form a conical tip 58 which seats in the small connectinglbore 39. The lower portion of bearing section 56 is provided with an annular groove 59 inwhich is seated an O ring 69. This 0 ring prevents the passage of any fluid from the lower region of bore 38. V

The flow of liquid from bore 43 and annulus 42 into the cross channel 51 and through orifice 53 is controlled by a closure member 61 which isnormally seated against the head of piston portion55 of pintle 54. This closure member is proportioned to snugly fit into bore 36 and counter bore 36a and is constructed asfollows: Starting at the upper end which, when the pintle isiin its closed position, will extend a substantial distance above the upper end of annulus 42 and continuing to the bottom edge of annulus 42, the diameter of section 62 of the closure member conforms with the diameter of counterbore 36a forming the larger upper bearing surface. The lower end of closure member s1 which comes in contact with the head of piston member 55 is proportioned to conform with the diameter of bore 36 and forms lower bearing surface 63. The diameter of the closure member is reduced between the bearing surfaces to form an annular channel 64 when the closure member is inserted into

bores

36 and 36a.

Since the diameter of counterbore 36a is greater than the diameter of bore 36 the diameter of the bottom surface of upper cylindrical bearing section 62 will be a little greater than the diameter of bore 36 thus forming a narrow annular contact surface 65. This surface may be ground to form a valve seat which will help prevent the flow of liquid into annular channel 64 when the pintle is in its closed position.

The upper bearing surface 62 is provided with a groove 66 positioned to be at all times above annulus 4-2. An ring 67 is inserted in this annular groove and prevents the liquid from flowing past annulus 42 into the upper portion or" counter bore 360 above the closure member 61. The lower bearing surface 63 is likewise provided wtih a groove 68 and an O ring 69 which prevents the flow of any liquid from either bore 45 or annular channel 64.

The upper end of cylindrical body 20 is closed by a cap 70 which preferably has a recessed portion 71, conforming with counterbore 36a. Cap 79 is provided wtih an annular groove 72 positioned a short distance from recessed portion 71 and in which may be seated a gasket 71%.

The construction of the valve assembly 12 employed in this apparatus is described in detail with reference to FIGS. 2, 6, 7, 8 and 9. The valve is the flutter or blade valve type; and is built up of an assembly of alternating flexible blades 75 and rigid channel members 76. Each of the channel members 76 comprises a rectangular plate 77, the upper surface of which is provided with a number of partitions 78 which are integral with plate 77 and run parallel to each other as shown. These partitions form a series of channels 79 which taper in depth being deeper at the leading edge 8t} and tapering at the rear edge 81 to coincide wtih the thickness of the rear edge of the blade 75 in assemblying the valve unit 12, several flexible blades 75 are alternately interleaved between the several channel members 76 and are firmly held near the leading edges 82 between the channel plate 77 of one channel member and the upper edge 99 of partitions 78 of the next channel member. These valves and rigid channel members are securely held together in a valve housing 193 by bolts 84 which pass through holes 85' provided in botn the flexible blades 75 and rigid channel members 7 as shown in FIG. 9. The central portion of the valve assembly is held in compression by a series of compression bolts 86 which press against a bearing plate 87. Valve housing 83 is shown as rectangular for convenience only but any other suitable shape may be employed. When a series of these valves and channel members are installed in the valve housing to form a completed valve assembly 12 they completely fill the space just preceding the reaction space 11. For purpose of assembly the completed valve slides into the valve housing 83 and is held in position by bolts 84, compression bolts 86 and shoulder shaped retainers 38 which are bolted to the forward portion of the sides of the valve channel 10.

FIGS. 7 and 8 are views illustrating the manner in which one of the blades is sandwiched between two of the channel members and FIG. 7 show a cutaway view looking into the channel member 76 showing its relation to a valve blade 75. The arrangement is such that the lower sides 39 of all flexible blades are enabled to vibrate so as to alternately contact and move away from the top edge 99 of partition members 78. This creates the valve action placing the valve in closed position when the blades 75 are against the top of partition member 78 and permitting the flow of liquid when the pressure against the valves from the forward side is sufficient to raise the rear portion of the valve leaf away from the top of channel partition member 78.

The operation of the unit will be better understood with reference to FIG. 10 which is a schematic drawing and FIG. 3 showing the manner in which the apparatus operates, A compressible gas, such as nitrogen, oxygen, air or other gas is introduced under pressure from tank 98 into the upper portion of bore 36a above the head of closure member 61 through threaded bore 49 and connecting passage 50, the pressure being maintained constant by any suitable regulating means such as a reducing valve 91.

A liquid such as oil is supplied to threaded bore 45 by a jerk pump 92, driven by a motor M, or any other suitable device Which can intermittently place the liquid under pressure. The use of a jerk pump to operate a pintle intermittently is described in the copending applicational Serial No. 652,430, filed March 6, 1946 entitled Injector. One outlet conduit from the jerk pump is connected to threaded hole 45 by a conduit 93 thus supplying liquid under pressure from pump 92, through connecting hole 46 and to the lower end of axial bore 36. This liquid under pressure acts against the bottom of piston-shaped member 55' causing it to raise Whenever the pressure against the bottom exceeds the pressure exerted by the gas cushion in the upper portion of bore 36a which is transmitted by closure member 61. Whenever the pressure exceeds that of the gas the pintle 54 moves upwards thus opening a continuous passage between annular channel 64 and annular groove 42, at the same time raising the closure tip 53 from the channel 39. One reacting liquid, water in this example, flows under pressure from its storage tank 94 through conduit 95, then into threaded bore 43, connecting passage 44 and into annular groove 42. The other reacting liquid under pressure is supplied from storage tank 96 through conduit 97, into bore 47, connecting conduit 98 into the lower annular space of bore 38 formed when the reduced diameter 57 of the pintle 54 is in position in bore 38. When the pressure against the bottom of piston member 55 is sufficient to raise pintle 54 and closure member 57 the liquid in the lower portion of the bore 38 will flow through orifice 39 into connecting channel 4i) and through a spiral channel 24 surrounding auxiliary reaction chamber 18, permitting the liquid to exit through orifices 35 provided in sleeve 26. A small portion of the liquid flowing through orifice 39 will also escape through orifice 41 into the auxiliary reaction chamber 18.

When the pintle and closure member are raised the annular space M will be facing both the annular groove 42 and transverse conduit 51 thus permitting liquid coming through connecting hole 44 to fiow from annular channel 42 into conduit 51, connecting channel 52 and through orifice '53. This liquid escaping through orifice 53 will impinge against the stream escaping through orifice 41, thus permitting the materials to react within the auxiliary reaction chamber 13. A suitable heating device 1495 will be required to keep the fuel in container as in a molten state and heated to the proper degree. Tank 94 is pressurized by gas in tank 98 and the pres sure is controlled by a regulating valve 99. Likewise tank 96 is pressurized by tank 94 and the pressure is controlled by a regulating valve tea.

The water reactive liquid passing through the spiral channel 24 will absorb heat that is produced by the reaction between the spontaneously reactive liquids coming in contact from

orifices

41 and 53 thus heating the main body of fuel and accelerating the rate of reaction between the water reactive material and the water in the reaction chamber 11. The conducting fins 29 assist in transferring a large portion of the heat developed by the reaction within the auxiliary chamber 18 to the sides of the spiral channel 24.

Since the device is submerged in water the entire reaction chamber 11 will be filled with liquid. The intermittent injection of the light metal propellant substance into the water at an intermittent rate produces intermitent reactions which intermittently raise the pressure in the chamber. At each intermittent increase of pressure the valve mechanism will close thereby forcing the reaction product along with the water out the entrance nozzle to produce the reaction thrust. Between these reactions in the chamber the valve will open to allow the water to enter, thereby providing the desired fiow of water through the duct.

Thus when the water reactive liquid escapes through the orifices 35 it will come immediately in contact with the water and spontaneously react with it. Whenever the pressure Within the main reaction chamber 11 drops below the pressure of the Water bearing against the incoming end of valve assembly 12 the valve blades 75 will open permitting scavenging and introducing a fresh charge of Water into the reaction chamber 11 and conduit 10.

The products of reaction from auxiliary reaction cham-' ber 18 escape through the auxiliary nozzle throat 19. By suitably proportioning the size of the nozzle H of the auxiliary jet motor it is possible to maintain a relatively high pressure within the auxiliary reaction chamber 18 at all times producing a substantially continuous discharge through the nozzle. This has the effect of smoothing out the low pressure periods between pulses which occur during the intervals when all injection orifices are closed.

- I prefer to use a propellant selected from a metal, metal hydride or organo-metallic compound which, at their critical temperatures, are reactive with water. However, I have found that those electropositive metals found in the electromotive series of the elements having electrode potentials of at least 0.7 volt and including all of the metals-having electrode potentials above this value, their hydrides, the organo-metallic compounds of these metals or their alloys, such as, for example sodium potassium alloy and an alloy of aluminum and magnesium called magnalium are the most effective propellants. Examples of the metals included in this group are lithium, beryllium, boron, sodium, magnesium, aluminum, silicon, potassium, calcium, scandium, titanium, rubidium, barium, manganese, tellurium and zinc. Thus, I may employ as a propellant a molten stream of sodium, lithium, or the like, a heated liquid stream of lithium hydride, sodium hydride, boron hydride, aluminum borohydride or the like, or a heated liquid stream of aluminum ethyl hydride, triethylboron, sodium methylate or the like.

The most desirable amount of heat above the melting point will vary with the different materials. For example, metallic sodium has a melting point of 97.5 C. and if heated to 110 C. will explode on contact with water, a differential of 12 /2 C., while potassium has a melting point of 623 C. and explodes in water at 69 C., a differential of only 6.7 C. On the other hand sodium potassium alloy K Na has a melting point of about 1 C. but will not explode in water until the temperature has been raised to 76 C., a differential of 77 C.

FIG. 11 shows graphically the effect of temperature upon the reaction rate of the metallic materials suitable for fuel which have been listed above. The curve shows a small increase in the reaction rate in the range between ambient temperatures and the melting point of the material. The substances exhibit a slightly greater increase in the reaction rate in the temperature range between the melting point of the material and its critical temperature above the melting point (1 critical). At t critical the reaction rate rises rapidly assuming almost a vertical slope until the material approaches its maximum reaction rate which is illustrated by the solid line in the curve. The term critical temperature as used in the specification and claims means that temperature above the melting point at which the reaction rate makes this sudden rapid rise. eyond the point at which maximum reaction rate is reached excess heatin appears to have no additional beneficial eifect. The dotted curve shows the path which the curve would be expected to follow if the above phenomena did not take place.

The advantages that are derived from operating the apparatus and process in the manner described above are as follows: Since the t critical is considerably lower in temperature than the temperature which would be required to reach an equivalent reaction rate (shown by the dotted line) if the above phenomena did not occur, the thermodynamic eificiency of the reaction cycle, that is, generation of hot H and the expansion of H with the accompanying scavenging stroke increases and causes:

(1) A high peak pressure p accompanied with a correspondingly high expansion ratio from the peak pressure to the exit pressure or the free stream pressure.

(2) The expansion from the high pressure p takes place so rapidly that the heat losses from the hot gases to the surrounding fluid are appreciably reduced.

(3) By increasing the diiferential between peak pressure and the exhaust pressure the degree of under pressure or suction obtained at the end of a work cycle from the system increases.

The low value of minimum pressure and the resulting suction possesses the advantage that the amount of thrust obtained during the scavenging stroke is increased and the cycling frequency can also be increased so that a higher cross section of specific thrust is obtained. This is defined as the total average thrust divided by the cross section of the duct.

Other variations and modifications will occur to those skilled in the art without departing from the spirit or scope of the foregoing description.

I claim:

1. In the operation through water of a reaction propelled device of the type having a duct provided with an inlet opening through which water is admitted, an exhaust nozzle through which water is ejected, a valve located in the duct and a reaction chamber between the valve and exhaust nozzle, the improvement which comprises heating a metallic water reactive propellant to cause it to melt, adding sufficient heat to heat the molten mass at least to the critical temperature above the melting point, injecting the molten material at a temperature at least as great as the critical temperature into the reaction chamber, and contacting the hot propellant liquid with the water within the reaction chamber thereby creating a violent reaction which creates pressure which closes said valve and creates an exhaust jet through the exhaust nozzle.

2. The improvement according to claim- 1 in which the water reactive propellant is a substance selected from the group consisting of electropositive metals in the elec tromotive series of the elements having electrode potentials of 0.7 volt or greater, alloys of these metals, and their organo-metallic hydrides.

3. The improvement according to claim 1 in which the water reactive substance is sodium.

4. The improvement according to claim 1 in which the water reactive substance is potassium.

5. The improvement according to claim 1 in which the water reactive substance is magnesium. 6. The improvement according to claim 1 in which the water reactive substance is lithium.

7. The improvement according to claim 1 in which the water reactive propellant is sodium potassium alloy.

8. The improvement according to claim 1 in which the water reactive propellant is aluminum borohydride.

9. The improvement according to claim 1 in which the water reactive propellant is ethyl aluminum hydride.

10. A reaction propelled device adapted for propulsion through a water medium, comprising a passageway having an inlet opening for permitting entry of water from the surrounding medium, an exhaust nozzle through which the water is ejected, an automatically operable valve located in said passageway, said valve being ope-rable to open to admit fluid from the medium when the pressure on the inlet side of the valve is greater than the pressure on the outlet side of the valve and closing the said valve when the pressure on the outlet side is greater than the pressure on the inlet side, a main reaction chamber between the valve and the nozzle, an auxiliary reaction chamber Within said reaction chamber, said auxiliary reaction chamber being provided with a nozzle discharging into said reaction chamber, means for injecting intermittently into said auxiliary reaction chamber a stream of water and simultaneously injecting into said auxiliary reaction chamber a stream of propellant, means for injecting intermittently into the main reaction chamber a water reactive propellant, heat transfer means for conducting the heat developed by the reaction in the auxiliary reaction chamber to the main water reactive propellant thereby heating it to a predetermined degree before it is injected into the water in the main reaction chamber and thereby causing its decomposition in developing intermittent pressure attended by the ejection of the products of reaction and water through the exhaust nozzle.

11. A reaction propelled device according to claim in which the nozzle attached to the auxiliary reaction chamber is proportioned to maintain at all times the positive pressure within said auxiliary reaction chamber.

12. A jet motor comprising a passageway for the entry of Water from the medium surrounding said jet motor, an exhaust nozzle through which said Water is ejected, means for introducing a metallic substance spontaneously reac tive with said water at a point intermediate between said passageway and said exhaust nozzle, means in association with said last named means for heating said substance to its critical temperature, and means in association with said passageway for stopping the entry of said fluid when the pressure at said intermediate point is greater than the pressure on the inlet side of said passageway.

13. A jet motor comprising a passageway for the entry of Water from the medium surrounding said jet motor, an exhaust nozzle through which said water is ejected, a main reaction chamber intermediate between said exhaust nozzle and said passageway, conduit means for introducing into said main reaction chamber a substance spontaneously reactive with said water, an auxiliary reaction chamber within said main reaction chamber in heat exchanging relationship with said conduit means and wherein a portion of said substance is caused to react spontaneously with water to add heat to said substance introduced into said main reaction chamber.

14. A jet motor according to claim 13 wherein said passageway is provided with means for controlling the flow of said fluid therein, said means comprising a flutter valve whereby the flow of fluid from said medium into said main reaction chamber is stopped when the pressure within said main reaction chamber exceeds the pressure exerted at the inlet point of said passageway.

15. A jet motor for operation through a fluid, comprising a primary reaction chamber, a passageway leading from the exterior of said motor into said primary reaction chamber, an exhaust nozzle in association with said reaction chamber and communicating with the exterior of said motor, a pressure responsive valve disposed within said passageway to permit the flow of fluid in which said motor is suspended only in the direction of said primary reaction chamber, an auxiliary reaction chamber within said primary reaction chamber, means for introducing a substance spontaneously reactive with said fluid into said auxiliary reaction chamber, means for introducing a quantity of said fluid, the same as said first-mentioned fluid, into auxiilary reaction chamber, means within said auxiliary reacting chamber for causing a portion of said substance to react with said fluid and for preventing the remaining portion of said substance from reacting with said'fluid whereby said remaining portion of said substance is heated, and means for introducing said remaining portion of said substance to said primary reaction chamber.

16. In the operation through water of a reaction propelled device of the type having a duct provided with an inlet opening through which water is admitted, an exhaust nozzle through which water is ejected, a valve located in the duct and a reaction chamber between the valve and the exhaust nozzle, the improvement which comprises intermittently injecting into the water in the reaction chamber a molten metallic water reactive propellant at a temperature which is at least as high as the critical temperature above the melting point at which the rate of reactionwith water rapidly increases, thereby producing intermittent reactions with great violence and creating pressures which close the valve intermittently thereby creating an exhaust jet through the exhaust nozzle.

17. The improvement according to claim 1 in which the water-reactive propellant is a substance selected from the group consisting of sodium potassium alloy, magnalium, lithium, beryllium, boron, sodium, magnesium, aluminum, silicon, potassium, calcium, scandium, titanium, rubidium, barium, manganese, tellurium, zinc, lithium hydride, sodium hydride, boron hydride, aluminum borohydride, aluminum ethyl hydride, triethylboron, and sodium methylate.

18. The improvement according to claim 1 in which the Water reactive substance is boron.

19. The improvement according to claim 1 in which the water reactive substance is silicon.

20. An injector for injecting molten fuel into a combustion chamber, comprising a spiral conduit adapted to be inserted within the chamber, a plurality of orifices through the spiral conduit to allow liquid to be injected from the spiral conduit into the chamber, a combustion region within the spiral conduit and means for injecting Water and also some of said liquid propellant into said combustion region to produce a reaction which will create heat to heat up the liquid travelling through the spiral conduit.

References Cited in the file of this patent UNITED STATES PATENTS 515,500 Nobel Feb. 27, 1894 870,308 McGonigle Nov. 5, 1907 1,656,486 Huntington et a1. Jan. 17, 1928 FOREIGN PATENTS 491,331 France Jan. 30, 1919 857,780 France Apr. 26, 1940 863,928 France Jan. 6, 1941 425,604 Great Britain Mar. 13, 1935