US3555824A

US3555824A - Gas generator construction and a method of operating a combustion chamber

Info

Publication number: US3555824A
Application number: US778205A
Authority: US
Inventors: Wilhelm G Buse; Heinrich Weigelt
Original assignee: Messerschmitt Bolkow Blohm AG
Current assignee: Airbus Defence and Space GmbH
Priority date: 1967-11-25
Filing date: 1968-11-22
Publication date: 1971-01-19
Anticipated expiration: 1988-01-19
Also published as: FR1592900A

Abstract

A ROCKET COMBUSTION ENGINE OR GAS GENERATOR COMPRISES A CYLINDRICAL HOUSING WHICH TERMINATES IN A THRUST NOZZLE AT ONE END FOR THE DISCHARGE OF GENERATED GASES AND WHICH INCLUDES AN OPPOSITE CLOSED END FOR DIRECTING A PROPELLANT COMPONENT, NAMELY, A LIQUID OXYGEN OR AN OXYGEN CARRIER INTO THE COMBUSTION CHAMBER. THE COMBUSTION CHAMBER IS LINED WITH A SOLID FUEL WHICH IS ADVANTAGEOUSLY DESIGNED AS A CENTRAL BURNER OR A COMBINATION CENTRAL AND END BURNER. THE SOLID FUEL DEFINES A CENTRAL PASSAGE FOR THE FLOW OF COMBUSTION GASES OR GENERATED GASES WHICH ARE ADVANTAGEOUSLY CONFINED FOR PASSAGE THROUGH A CENTRAL OPENING OF A PLATE ADJACENT THE DISCHARGE THRUST GAS NOZZLE. THE OXYGEN IS INTRODUCED IN A MANNER SUCH THAT IT WHIRLS ALONG THE INTERIOR WALL OF THE COMBUSTION CHAMBER, AND FOR THIS PURPOSE IT MAY BE INTRODUCED BY A TURBULENCE NOZZLE MEMBER OR BY INTRODIRECTION IN A TANGENTIAL MANNER INTO A PRECHAMBER WHICH LEADS INTO THE CLOSED END OF THE COMBUSTION CHAMBER. A SOLID FUEL IS DESIGNED AS A CYLINDER WHICH ABUTS AGAINST THE CLOSED END WALL AND WHICH RESTS ON A RING PLATE LOCATED ADJACENT THE NOZZLE OR OPPOSTE END. THE END ADJACENT THE NOZZLE MAY ADVANTAGEOUSLY BE FORMED IN A CURVED MANNER SO THAT THE OXYGEN MAY FLOW IN A WHIRLING STREAM IN A SMOOTH MANNER AGAINST THE END WALL THEREOF. COMBUSTION TAKES PLACE HYPERGOLICALLY OR IF THE PROPELLANT COMPONENTS ARE NOT OF A TYPE TO REACT HYPERGOLICALLY THEN AN ADDITIONAL MIXTURE TO PROMOTE HYPERGOLIC REACTION AND IGNITION WITH THE OXYGEN IS INTRODUCED.

Description

Jan. 19, 1971 w, usg ETAL 3,555,824

GAS GENERATOR CONSTRUCTION AND A METHOD OF OPERATING A comsusmpu CHAMBER Filed Nov. 22, 1968 3 Sheets-Sheet l INVENTORS Wilhelm Gfiuse Heinrich Wei' elt By German Mun ing 7 7 1 ATTOREYS GAS GENERATOR CONSTRUCTION AND A METHOD OF OPERATING A COMBUSTION CHAMBER Filed NOV. 22, 1968 3 She138-$heet Fig.3

INVEM'ORE:

WiCh WGQ QH By German Wsdfigg ht MTMW ATTORNEYS 19, 1971 w. G. BUSE ETAL Jan. 19, 1971 w. G. BUSE ETA!- 3,555,824

GAS GENERATOR CONSTRUCTION AND A METHOD OF OPERATING A COMBUSTION CHAMBER Filed Nov. 22, 1968 3 Sheets-Sheet 3 5 8 5 M ymn T N NG MR w e um W m W M United States Patent 3,555,824 GAS GENERATOR CONSTRUCTION AND A METHOD OF OPERATING A COMBUSTION CHAMBER Wilhelm G. Buse, Egmating, German Munding, Kochendorf, and Heinrich Weigelt, Degmarn, Germany, assignors to Messerschmitt-Bolkow Gesellschaft mit beschrankter Haftung, Munich, Germany Filed Nov. 22, 1968, Ser. No. 778,205 Claims priority, application Germany, Nov. 25, 1968, 1,626,071, 1,626,072 Int. Cl. F02]: 9/04 US. Cl. 60-220 18 Claims ABSTRACT OF THE DISCLOSURE A rocket combustion engine or gas generator comprises a cylindrical housing which terminates in a thrust nozzle at one end for the discharge of generated gases and which includes an opposite closed end for directing a propellant component, namely, a liquid oxygen or an oxygen carrier into the combustion chamber. The combustion chamber is lined with a solid fuel which is advantageously designed as a central burner or a combination central and end burner. The solid fuel defines a central passage for the flow of combustion gases or generated gases which are advantageously confined for passage through a central opening of a plate adjacent the discharge thrust gas nozzle. The oxygen is introduced in a manner such that it whirls along the interior wall of the combustion chamber, and for this purpose it may be introduced by a turbulence nozzle member or by introdirection in a tangential manner into a precharn ber which leads into the closed end of the combustion chamber. A solid fuel is designed as a cylinder which abuts against the closed end wall and which rests on a ring plate located adjacent the nozzle or opposite end. The end adjacent the nozzle may advantageously be formed in a curved manner so that the oxygen may flow in a whirling stream in a smooth manner against the end wall thereof. Combustion takes place hypergolically or if the propellant components are not of a type to react hypergolically then an additional mixture to promote hypergolic reaction and ignition with the oxygen is introduced.

SUMMARY OF THE INVENTION This invention relates in general to the construction of gas generators and in particular, to a new and useful rocket combustion engine having a combustion chamber with a solid charge therein and with means for admitting a liquid oxygen or oxygen carrier in a manner such that it is whirled into association with the combustion chamber walls and the solid charge and advantageously reacts hypergolically with the solid charge and to the method of operating such an engine.

The gas .generator of the present invention is of a type which employs a solid fuel or one that cannot react by itself without the supply of an additional (liquid) oxygen carrier. Gas generators of a hybrid type having a solid fuel lining the combustion chamber are known. Such generators use a liquid ergol having hypergolic properties which is fed during the operation of the engine. A liquid 3,555,824 Patented Jan. 19, 1971 ergol may be introduced at the upstream end of the combustion chamber in which a solid ergol in the form of several serially arranged lithergols of different chemical compositions are arranged so that a passage for the escape of the substances participting in the rection is let free. At least a lithergol portion arranged in the proximity of the zone into which the liquid ergol is injected contains a volatile substance which reacts hypergolically with the liquid ergol. The introduction of the liquid ergol (which for example might be a liquid nitric acid) into the combustion chamber is effected through a centrally arranged atomizer nozzle and it is directed to the cylindrical inner surface of the first lithergol section. In order to obtain a long stay period in the first and also in the following combustion zones of the combustion chamber and thereby achieve a higher combustion chamber eificiency and a better combustion it has been known to employ obstacles in the form of perforated diaphragms in the current stream between the various lithergol zones so that turbulence is produced in the various combustion compartments which will intensify the contact between the oxygen rich initial gas current and the solid fuel parts. The stay period is extended by division of the combustion into individual combustion compartments by means of the perforated diaphragms and the erosion of the fuel is accelerated thereby. A known arrangement, however, has a disadvantage that the solid residues which are not burned at the end of the combustion chamber remain in the radial outer dead corners of the individual components and they are unaffected or hardly affected by turbulent fiow and this impares the eificiency 0f the combustion chamber. A division of the combustion chamber by the perforated diaphragms into individual compartments is no absolute assurance of the optimum operation of the combustion chamber since a very great delay of the flow between the various combustion chamber zones will have an unfavorable eifect. In addition, there is a possibility toward the end of the operation of the combustion chamber that the regionally unprotected housing wall in the front section of the combustion chamber will burn through because of the exposure of the parts of the combustion chamber wall due to the partial dissolution of the fuel block contained there.

The disadvantages of the prior art are overcome by providing, in accordance with the invention, a combustion chamber which is lined with a solid charge and which is charged with a liquid oxygen carrier in a manner to form a whirling layer of oxygen which bears against the inner surface of the combustion chamber wall and the burn ofl zone of the solid charge. The construction provides for a high specific output of the combustion chamber and ensures practically complete combustion within the combustion chamber. The construction is an improvement over the prior art particularly in respect to the use of liquid oxygen in conjunction with the solid charge in an arrangement such that the oxygen will bear against the wall of the combustion chamber and the solid charge and optimum combustion results.

In accordance with one embodiment the liquid oxygen is introduced by a whirling nozzle device adjacent the closed end of the combustion chamber and it is directed as a whirling tangentially introduced layer against the end face of the combustion chamber and against the interior cylindrical bore of the solid charge which is arranged to abut against the end face. In an alternate arrangement the solid charge is shaped at the end face to provide for a curved surface leading up to the nozzle discharge for the oxygen carrier so that the oxygen will be whirled in an even smooth layer over the surface. A still further embodiment includes a prechamber which is supplied tangentially from an annular oxygen supply duct so that the liquid oxygen is introduced in a whirling stream into the prechamber and whirled as an overflow into the closed end of the combustion chamber and against the wall of the bore of the solid charge.

In still another embodiment the solid charge is spaced from the closed end of the combustion chamber and its end face defines a partial fore combustion chamber in which there is initial ignition and burning off of the end face. A modified version provides for a curved form of charge at the end face adjacent the closed end of the combustion chamber so as to define a partially spherical fore combustion chamber.

Accordingly, it is an object of the invention to provide a method of operating a gas generator having a solid charge with a bore therethrough for passage of the combustion gases which includes directing a liquid oxygen into the closed end of the combustion chamber adjacent the solid charge in a manner such that the oxygen flows as a whirling film along the walls of the combustion chamber and adjacent the walls of the solid charge and provides a progressive interreaction therewith hypergolically as the oxygen flows along the length of the charge to generate combustion gases which then flow outwardly from the combustion chamber.

A further object of the invention is to provide a combustion chamber construction in which the combustion chamber is lined with a solid charge having a through bore defined therethrough, and including a means for whirling a liquid oxygen carrier into the combustion chamber so that it moves outwardly against the walls of the chamber and into whirling contact with the solid charge in the form of a thin veil and reacting layer.

A further object of the invention is to provide a rocket combustion engine which includes a solid charge arranged against the walls of the combustion chamber and having a central bore through which combustion takes place and the reaction gases pass, the charge being supported on a perforated plate preferably having a single opening for centering the discharge gases in respect to a discharge nozzle and including a means for either directly introducing liquid oxygen in a whirling stream or for introducing it first into a precham'ber and then whirling it into the combustion chamber adjacent the solid charge.

A further object of the invention is to provide a combustion chamber which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is an axial sectional view of a rocket engine constructed in accordance with the invention;

FIG. 2 is a partial sectional view similar to FIG. 1 of another embodiment of the invention;

FIG. 3 is a partial axial sectional view similar to FIG. 1 of still another embodiment of the invention;

FIG. 4 is a section taken on the line IV-IV of FIG. 3;

FIG. 5 is an axial sectional view similar to FIG. 1 of Still another embodiment of the invention; and

FIG. 6 is a partial axial sectional view of still another embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings in particular, the invention embodied therein in FIG. 1 comprises a rocket engine generally designated 50 having a cylindrical portion 1, a closed end 1a and a gas discharge end 1b terminating in a thrust nozzle 12 for the discharge of thrust gases.

In accordance with the invention, the cylindrical combustion chamber 1 is lined with a solid fuel 2 which is designed as a hollow burner and extends from the closed end It: to a perforated plate 3 which is located adjacent the discharge end 1b. The perforated plate 3 includes preferably a single opening 3a located centrally in respect to the combustion chamber and the discharge nozzle 12. A turbulence nozzle or propellant whirling device 4 is arranged centrally at the closed end 1a of the combustion chamber and it is provided with means for directing liquid oxygen or an oxygen carrier from an oxygen supply conduit 52 into the combustion chamber 10 defined within the bore of the solid charge 2 in the form of a whirling stream or layer of the liquid oxygen. The oxygen or oxygen carrier S flows in a whirling stream along the end wall 1a and then progressively flows in a thin layer along the interior walls of the solid charge 2 and continuously reacts hypergolically with the solid fuel. After the liquid oxygen passes through a certain initial zone a in which an oxygen rich precombustion takes place there is an evaporation of the liquid oxygen carrier S and a gaseous hot oxygen-rich twist current 11 is produced. Due to the centrifugal action of the twist current 11 the remaining less hot oxygen carrier gas particles are constantly displaced to the periphery of the twist current 11 and fed through a hot reaction layer which continuously forms in a small area over the inner surface 9 of the solid charge 2. This hot reaction layer of oxygen or oxygen carrier gas reacts with the fuel particles which evaporate from the solid fuel 2 and the reaction gases push outwardly from the hot reaction layer toward the center of the twist current 11. Consequently a constant separation takes place in the twist current 11 between hot reaction gases and the less hot oxygen carrier gases. The twist current 11 has the additional effect that the hot reaction layer is present closer to the inner surface of the solid fuel 2 so that the evaporation of the solid fuel is accelerated by the increased heat transfer.

The intensity of the twist and the forward tendency of the twist current is selected in accordance with the size of the combustion chamber and its length and the length of the solid fuel 2. In addition, consideration is given to the reaction velocity which results from the chemical substances of the two propellant components so that complete combustion is ensured up to the end of the combustion chamber 10.

The perforated diaphragm 3 provides a constriction to ensure that only the hot current core which is posit1vely completely reacted and contains no unburned gas particles leaves the combustion chamber. A stay period is forced upon the layers of the gaseous twist current 11 which are located close to the surface of the solid fuel 2. The opening 3a of the plate 3 is advantageously centered so that the hot core may pass as thrust gases for discharge through the nozzle 12.

In the embodiment indicated in FIG. 2, a gas generator 54 is disclosed which includes a combustion chamber 10 formed within the core of a solid charge 2. The solid charge 2 is curved as at 2a adjacent the closed end 1a of the combustion chamber. An oxygen carrier S is introduced through a conduit 56 and it is discharged by a whirling nozzle 4, in a manner such that it flows as a film along a wall of the solid charge 2'. The operation of this device is similar to that indicated in FIG. 1.

In the embodiment indicated in FIGS. 3 and 4 there is provided a gas generating device generally designated 58 which comprises a cylinder 60 having an end wall defining a twist chamber 5a with a central opening or weir 6 for directing an oxygen carrier Sa in the form of a whirling stream overflowing into the combustion chamber 10" formed at the core of the solid charge 2". Liquid oxygen S is introduced to the inner surface of the twist chamber 5a through tangential inlet bores 7 which are supplied from an annular conduit 8. The liquid oxygen carrier or oxygen carrier vapor Sa flows from the twist chamber 5a against the wall of the solid charge 2' and forms a gaseous hot oxygen rich twist current 11" as indicated in the other embodiments. The twist chamber 5a produces not only the twist current necessary for directing the oxygen along the length of the solid charge 2 but also partially evaporates the oxygen in order to facilitate the reaction thereof with the solid charge material.

In the embodiments of FIGS. 3 and 4, the portion of the oxygen carrier vapor Sa which strikes the front part of the solid fuel is greater than in the embodiment of FIG. 1 due to the presence of the twist chamber 5a which acts as an evaporation chamber in full operation. This fact enhances the course of the combustion process according to the invention insofar as the initial zone a" of FIG. 3 and the initial phase during which the liquid oxygen carrier must be converted into vapor is shortened so that combustion process is intensified.

The liquid oxygen carrier S is introduced into the closed end of the combustion chamber in a form of a narrow twist current with a small axial velocity vector so that a high local concentration of oxygen carrier strikes the front part of the solid fuel 2, a sort of pre combustion chamber is created in the initial state of the combustion chamber operation by intensive erosion of solid fuel in the front region of the solid fuel 2". This results in an increased production of oxygen rich gases in the region adjacent the closed end wall of the combustion chamber because a certain return flow will take place in the precombustion chamber which is formed by the erosion effect and this will result in an additional stay period for the products being burned. A similar arrangement is shown by the reinforcement 2a in the embodiment of FIG. 2 but the latter is shaped so that the erosion is uniform and smooth and it provides for a smooth flowing of the oxygen carrier without obstruction. It is also possible to make the front portion of the solid fuel 2' or the solid of the embodiment of FIG. 2 or that of the solid charge 2 of the embodiment of FIG. 3 of a chemical substance which has a longer reaction time so that the radial decomposition of the solid fuel will remain the same over the entire length of the charge.

The variants indicated in FIGS. 3 and 4 and that of FIG. 2 provides solutions which can be used from case to case depending upon the requirements for the combustion chamber. The construction of FIGS. 3 and 4 in which the precombustion chamber must be hollowed out by the liquid oxygen carrier as it flows over the solid charge will have a favorable combustion efliciency once the charge is hollowed out to form a precombustion chamber having a very short length. By forming the charge to provide for the smooth transition flow of the oxygen carrier, however, as in the embodiment of FIG. 2, a very favorable efiiciency with high power concentration over the entire power operation is obtained with a greater overall length of the combustion chamber.

According to the invention, the hypergolic combustion process is the preferred operating method. But a nonhypergolic combustion is not impossible provided an ignition mixture is introduced into the combustion chamber in addition to the other propellant components so that it reacts with the other components during the initial phase of the combustion chamber operation, or during the entire operating time which is hypergoloid with the oxygen carrier. The heat of this process will serve as an additional reaction catalyst. The external ignition with one or several spark plugs or glow plugs is also possible. By utilizing the favorable aspects of an oxygen carrier introduced into the combustion chamber in a whirling layer or twist form favorable combustion chamber efiicie-ncies and high specific combustion chamber performances especially with hypergolic gas generators is achieved according to the invention in a simple manner.

In the embodiments of FIG. 5 a rocket engine 62 is provided which comprises a cylindrical combustion chamber shell 26 which is lined with a solid fuel 21 designed as a' hollow burner but having a rear end portion 21a which also functions as an end burner. The charge 21 is supported on a diaphragm 22 which has a central opening 22a arranged centrally in respect to a nozzle discharge 31. A charge 21 is spaced from an end face 23 of the closed end of the cylindrical shell 26 and it defines a precombustion chamber 24 between the closed end face 23 and the end 21a of the solid charge 21. A turbulence nozzle 25 is arranged in the closed end and it is oriented to discharge liquid oxygen as in a whirling stream adjacent the closed end 23 of the combustion chamber. The liquid oxygen deposited on these walls of the combustion chamber will provide a cooling effect thereon and the return whirling flow thereof along the end face 21a causes an inter-reaction with the charge material and combustion. This causes a progressive erosion of the solid fuel 21 by the oxygen carrier S and a hypergolic reaction between the two substances takes place. The released reaction heat causes a continuous evaporation of the liquid oxygen carrier S. The underpressure produced by the twist current in the central region of the precombustion chamber 24 produces a return zone of flow as indicated by the arrows 27 so that a complete or at least a predominant evaporation of the liquid oxygen carrier S which has already been introduced is ensured at the location of the precombustion chamber 24 due to the inforced stay period. A first combustion phase thus takes place in the precombustion chamber 24 which produces an oxygen rich gas which then flows through the bore 30 of the solid charge 21 as indicated by the line flow 28. This causes an erosion of the interior wall of the solid charge 21 and the reaction of the oxygen rich current oxygen 28 with the solid charge 21. The oxygen carrier particles which are less hot are pushed to the periphery of the twist current 28 and thus brought into the vicinity of the range of the inner surface 30 where they react with the fuel particles which are already evaporated by the process heat. The hotter reaction gas is pushed toward the center of the twist current 28 so that a constant separation between the hot reaction gases and the less hot oxygen carrier gases take place within the twist current flow.

In order to kindle the ignition a small part of the oxygen carrier S can be injected in an atomized form toward the front end wall 21a of the solid charge 21.

In the embodiment of FIG. 6 there is provided a gas generator generally designated 64 having a solid charge 21' with a curved end face 21a in a bore 29' providing a central flow channel. The curved end face 21a defines a substantially spherical precombustion chamber 24a with the end wall 23'. The curved wall configuration of the charge 21 provides a greater reaction surface for the liquid oxygen 6 which is introduced through the whirling nozzle 25' so that heat produced during the initial phase of the combustion process in the precombustion chamber portion 24a is increased and the evaporation of the liquid oxygen carrier S is intensified both in terms of time and quantity. In addition, this construction is particularly suitable for the formation of a central return zone 27. In this embodiment the oxygen carrier may be introduced without twisting if so desired. Even in the straight current introduction in the form of the two streams indicated will produce a whirling flow within the precombustion chamber 24a which is defined on the curved end face portion 21a of the solid charge 21. A reaction will take place between the oxygen rich gas current and the evaporated solid fuel particles in a hot reaction layer formed above the inner surface 30' of the solid fuel 21' mainly because the colder unreacted oxygen rich gas particles are pressed to the periphery of the current by the hotter rapidly expanding reaction gases which flow at a more rapid rate toward the combustion chamber outlet.

What is claimed is:

1. A gas generator, comprising a tubular member defining a combustion chamber having a closed end and an opposite gas discharge end, a solid propellant charge in said combustion chamber having at least a peripheral portion engaged with said tubular member and having at least one through passage defined therethrough from the closed end of said combustion chamber to the opposite gas discharge end, means for directing the entire amount of an oxygen propellant component in the form of a whirling stream into said combustion chamber from the closed end against and along said propellant charge for movement through the entire passage thereof, and means for causing interreaction of said propellant compo nents together and the generation of a turbulent gas stream in said combustion chamber proceeding through the passage to said gas discharge end.

2. A gas generator, according to claim 1, wherein said means for causing interreaction of said propellant components comprises a solid propellant charge and an oxygen propellant component which react hypergolically.

3. A gas generator, according to claim 1, wherein said means for directing an oxygen propellant component into said combustion chamber comprises nozzle means for whirling liquid oxygen into said combustion chamber in the form of a whirling film.

4. A gas generator, according to claim 3, wherein said whirling film of oxygen bears against the closed end of said combustion chamber initially and then flows through said passage of said propellant charge in engagement with the walls of said through passage.

5. A gas generator, according to claim 4, wherein said propellant charge is spaced from the closed end of said combustion chamber and defines a precombustion chamber in a space between its end and the closed end of said combustion chamber.

6. A gas generator, according to claim 4, wherein said propellant charge extends to the closed end of said combustion chamber but has a through passage therethrough of a diameter suflicient to expose a portion of the closed end wall of said combustion chamber, said oxygen propellant flowing over the portion of said closed end of said combustion chamber and then against the walls of the propellant charge adjacent the through passage.

7. A gas generator, according to claim 4, wherein said propellant charge extends to said closed end and has a curved end portion extending substantially to the center of said combustion chamber, said means for directing oxygen propellant into said combustion chamber comprising a nozzle located centrally at the closed end of said combustion chamber, and in a position to direct oxygen propellant initially along the curved portion of said propellant charge.

8. A gas generator, according to claim 4, wherein said propellant charge is provided with a recessed end portion of substantially spherical configuration located adjacent the closed end of said combustion chamber and providing a precombustion chamber of a shape to provide for return flow of the combustion gases which interact in a precombustion chamber prior to a fiow through said through passage.

9. A gas generator, according to claim 1, wherein said means for directing an oxygen propellant component into said combustion chamber comprises a prechamber, means for tangentially introducing oxygen into said prechamber, said prechamber having a central connection to the closed end of said combustion chamber forming a weir for which the whirling liquid oxygen is directed into said combustion chamber.

10. A gas generator, according to claim 1, including a plate having an opening therethrough arranged adjacent the discharge end of said combustion chamber, the opening being aligned with the through passage of said propellant charge.

11. A gas generator, according to claim 10, wherein the discharge end of said combustion chamber includes a thrust nozzle discharge, a plate arranged in said combustion chamber adjacent said thrust nozzle discharge and extending across said combustion chamber, said plate being perforated and having at least one perforation located in alignment with the through passage of said propellant charge, said discharge end having a thrust nozzle discharge aligned with the opening of said plate, said propellant charge being supported on said plate.

12. A gas generator, according to claim 11, wherein said plate has a single opening of a diameter smaller than the through passage of said propellant charge, said through passage comprising a central bore defined through said charge, said charge being substantially cylindrical.

13. A gas generator, comprising a tubular member defining a combustion chamber having a closed end and an opposite gas discharge end, a solid propellant charge in said combustion chamber having at least a peripheral portion engaged with said tubular member and having at least one through passage defined therethrough from the closed end of said combustion chamber to the opposite gas discharge end, means for directing an oxygen propellant component against and along said propellant charge for movement through the passage thereof, means for causing interaction of said propellant components together and the generation of a turbulent gas stream in said combustion chamber proceeding through the passage to said gas discharge end, a plate having an opening therethrough arranged adjacent the discharge end of said combustion chamber, the opening being aligned with the through passage of said propellant charge, means defining a shallow depth whirl chamber at the closed end of said combustion chamber having a central opening, and an annular duct for oxygen connected tangentially into said whirl chamber for whirling liquid oxygen into said chamher and for overflowing the oxygen into said combustion chamber.

14. A method of operating a combustion chamber having a hollowed interior solid propellant component charge which reacts hypergolically with liquid oxygen arranged in a combustion chamber having a closed end and a passage through the charge from the closed end to a thrust nozzle leading to a discharge at the opposite end, comprising directing all of the liquid oxygen into the combustion chamber adjacent the closed end and in a whirling flow to form a layer of oxygen which proceeds along the interior walls of the charge from the closed end to the discharge end of the combustion chamber.

15. A method according to claim 14, wherein the combustion chamber includes a whirling chamber, comprising introducing the oxygen into the whirling chamber before it is directed into the combustion chamber with a force and direction to cause it to flow outwardly from the whirling chamber into the combustion chamber and along a portion of the walls of the combustion chamber before contacting the charge.

16. A method according to claim 14, comprising directing the liquid oxygen into a whirling return flow adjacent the closed end of the combustion chamber and adjacent an end face of the propellant charge, and then permitting the oxygen to flow along the walls of the propellant charge to the discharge of the combustion chamber.

17. A method, according to claim 14, including discharging the gases generated by interreaction of the proellant components through a thrust nozzle, and confining the generated gases centrally in respect to the passage of the propellant charge and permitting discharge of only the 3,106,162 10/ 1963 Hagerty 60251X central portion of the gas stream. 7 3,136,119 6/ 19 64 Avery 60251X 18. A gas generator according to claim 5, including 3,142,152 7/ 19'64 Sessums 60--251 means for directing a small amount of said oxygen 3,274,775 9/1966 Berton 60-39.47 propellant component against the end face of said 5 3,298,181 1/ 1967 Greiner 60251 propellant charge. 3,315,472 4/1967 Moutlet et al. 60251 References Cited CARLTON R. cRoYLE, Primary Examiner UNITED STATES PATENTS 2,974,476 3/1961 FOX 60 255 CL 3,015,209 1/1962 Geckler 60225 60-251, 39.46