US2627720A

US2627720A - Circumferentially arranged combustion chamber with arcuate walls defining an air flow path between chambers

Info

Publication number: US2627720A
Application number: US53438A
Authority: US
Inventors: Robert M Williams; George F Wislicenus
Original assignee: Packard Motor Car Co
Current assignee: Packard Motor Car Co
Priority date: 1948-10-08
Filing date: 1948-10-08
Publication date: 1953-02-10
Anticipated expiration: 1970-02-10

Description

1953 R M WILLIAMS ETAL 7,

CIRCUMFERENTIALLY ARRANGED COMBUSTION CHAMBER t WITH ARCUATE WALLS DEFINING AN AIR FLOW PATH BETWEEN CHAMBERS 4 Sheets-Sheet 1 Filed Oct. 8, 1948 Feb. -I0, 1 953 RFM. WILLIAMS ET AL 2,627,720

' CIRCUMFERENTIALLY ARRANGED COMBUSTION CHAMBER WITHARCUATEJWALLS DEFINING-AN AIR mow PATH BETWEEN CHAMBERS Filed Oct. 8, 1948 4 Sheets-Sheet 2 Feb 1953' R. M. WILLIAMS Er'AL- 2,527,720

CIRCUMFERENTIALLY ARRANGED COMBUSTION 'CHAMBER WITH ARCUATE WALLS DEFINING AN AIR FLOW PATH BETWEEN CHAMBERS- Filed on. a, 1948 4 Sheets-Sheet s Feb. .10, 1953 R. M. WILLIAMS ET AL. 2,627,720

CIRQUMFERENTIALLY ARRANGED COMBUSTION CHAMBER WITH ARCUATE WALLS DEFINING AN AIR FLOW PATH BETWEEN CHAMBERS Filed Oct. 8, 1948 4 Sheets -Sheet' 4 U U H l] U U U fioberzjyi/ ifigm BY GeozgeFZZ/zlskcema,

QM, 44. WM ZQ 0 Patented Feb. 10, 1953 CIRCUMFERENTIALLY ARRANGED COM- BUSTION CHAMBER WITH ARCUATE WALLS DEFINING AN AIR FLOW PATH BETWEEN CHAMBERS Robert M. Williams, Toledo, Ohio, and George F.

Wislicenus, Baltimore, Md., assignors to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application October 8, 1948, Serial No. 53,438

12 Claims.

The invention relates generally to gas turbine units and more particularly to the structure of the combustion chamber portion of the unit and the relation of such portion to other portions of the unit.

In a gas turbine unit of the type herein contemplated, an air compressor or impeller may be employed to force air into the unit. Heat is then added to the air stream and a portion of the energy in the stream is utilized to operate a turbine to drive the compressor. The air stream issuing from the impeller has a relatively high velocity, which renders it diincult, if not impossible, to maintain combustion the-rein. A diffuser portion or section is therefore frequently included in the structure of the unit, where the velocity of the air i reduced sufficiently to maintain combustion in the adjoining combustion chamber portion. The necessity of utilizing a diffuser entails some disadvantages. Thus, it not only requires space in the structure of the unit, but it also involves some loss of efficiency. The impeller of the compressor may have an efficiency on the order of 90% or higher, While the difiiuser may have a substantially lower efficiency, say, on the order of 70%.

The general object of the invention is therefore to provide a novel gas turbine in which the major portion of the air stream may flow at an aerodynamically optimum velocity without restriction due to requirements of combustion.

Another important object is to provide a novel gas turbine in which only a minor portion of the air stream need be subjectedto substantial retardation to provide for combustion.

A further important object is to provide a novel ga turbine in which combustion and diffusion may be said to overlap, or in other words, a gas turbine in which both combustion and retardation of the flow may occur in one portion of the path of air stream in the unit.

Still another object is to provide a novel gas turbine in which the combustion chamber structure as well as the combustion gas emerging therefrom are completely surrounded or encased by the air stream so that adjacent structure of the unit is prevented from being overheated.

A still further object is to provide a gas turbine in which mixing of the air stream and the relatively hotter combustion gas is effected in a novel manner so that the resultant power stream is of substantially uniform temperature throughout.

Another object is to provide a novel gas turbine having an airpassage through which air is delivered by the impeller and in which are vanes controlling the flow of the air therein, and a combustion portion forming a continuation of such passage and provided with combustion chamber walls constituting in effect a continuation of said vanes.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings, in which:

Figure 1 is a side elevational view, with a portion thereofbroken away, of a gas turbine embodying the features of the invention.

Fig. 2 is a view, on a larger scale, of the brokenaway portion shown in Fig. 1.

Fig. 3 is a fragmentary perspective view of the portion of the structure shown in Fig. 2.

relates particularly to the structure of the combustion chamber section'of the unit and its relation to the air compressor section. In the type of gas turbine herein contemplated, air is drawn inwardly through an air intake opening at the front of the unit, by means of a rotatively driven air impeller. The air discharged by the impeller has a helical movement, and for this reason the delivery end of the air passage in the aircompressor section, known as acollector, is provided with helically arranged guide vanes.

. a In gas turbines of this type, a diffuser is frequently employed immediately downstream from the air compressor section to receive the air stream from such compressor section and to diffuse or lower the velocity of the air. From the diffuser, the air stream flowsintothe combustion chamber section, where heatenergy is added to the air v stream byrthecombustion of fuel. The reduction of velocity of the air stream in the diffuser is 'sufficient'lto permit; combustion to, be maintained in thecombustionchamber section.

In the present construction, .the diffuser and combustionchamber sectionare united or overlapped, and the air stream therein is-handled in such a manner that the major portion thereof flows at an aerodynamicallyoptimum velocity without restrictionbecause of combustion. Thus.

very little retardation on the major portion of the air stream may be required, while only a minor portion of the air stream is subjected to any substantial degree or" retardation, and the combustion takes place in such minor portion. With this arrangement, the major portion, in which very little retardation has occurred, readily mixes with the combustion gases emerging from the combustion chamber. This result is accomplished by positioning a plurality ofcombustion chamber members in the path of the air stream as it leaves the collector or the delivery end of the compressor section, with the combustion chamber members spaced from one another so that the major portion of the air stream may flow therebetween. Such air as is needed in the combustion chamber members to support combustion therein is withdrawn from the air stream passing between the members and is permitted to enter the combustion chamber members for combustion of the fuel with a velocity therein suitable for such combustion,

The combustion chamber members cooperate with the guide vanes in the delivery end of the compressor section, and are shaped to control the direction of flow of the air stream. Thus, in the illustrative embodiment shown in the drawings, the members are shaped to reduce the helical character of movement of the air stream so that th stream thereupon flows substantially only in an axial direction. Because'of this function, they are nonsymmetrical in form. The combustion chamber members are supported in such a manner that the air stream flows not only between the respective members, but also between them and the adjacent casing structure so that each member is completely encased by a flow of relatively cool air, thus reducing the heat transmitted to the adjacent casing structure and other parts of the unit. At the discharge end of the combustion chamber members, the emerging combustion gases are likewise encased by the air stream so that not only is the surrounding structure in that portion of the unit protected from overheating, but the mixing of the air stream with the combustion gases is greatly facilitated.

The gas turbine utilizing the features of the invention is shown in Fig. 1 as a jet propulsion unit. As illustrated, the unit comprises an intake nozzle l9 provided with an'annular front opening nozzle ll.

As shown in Fig, 2 of the drawings, the compressor section H includes a rotary impeller 26 provided with blades 2! for creating an air stream directed both radially and rearwardly into the delivery portion 53, the air stream having a helical movement. Provided in the collector i3 is a plurality of guide vanes 22, between which the air flows into the combined difiuser and combustion chamber section It. The impeller 28, in the pres ent instance, is carried on a tubular shaft 23 driven by the turbine in the turbine section 15. It. will be noted that the air stream delivered through the delivery portion iii-emerges therefrom in a generally rearward direction with a slight inward component, the air, however, maintaining its helical movement as heretofore mentioned.

The combined diffuser and combustion chamber section M comprises an annular inner casing 24 and an annular outer casing 25 enclosed by an outer shell 25. The

casings

24 and 25 are in spaced relation to each other to provide an annular passage 25 to receive the air flow. As clearly shown in Fig. 2 of the drawings, both casings are of a conical shape with their smaller ends facing in a downstream direction, but the inner casing member 2 1 slopes inwardly at a steeper degree than the outer casing member 25, so that the passage therebetween, while decreasin in diameter, increases in its radial width.

The upstream end of the annular passage 25' between the casings 2d and 25 is where combustion takes place, while the downstream end of such annular passage is utilized for mixin of the combustion gases with-the major portion of the air stream, the quantity of air delivered by the compressor being much greater than is necessary to support the combustion. Because of the quan tity of air that is forced through the unit by the impeller, its velocity is so great that combustion must be protected from the flow so that such coinbustion may be maintained. To this end, a plurality of hollow combustion chamber members, indicated generally at 2?, are mounted inthe annular passage 25' between the casings 25- and 25 adjacent the upstream end thereof, with said members positioned in circumferentially spaced relation to each other so that the major portion of the air stream may pass therebetween. Such combustion chamber members are provided with an openingso that a minor portion of the air passing therebetween is withdrawn into the members to support combustion therein at a reduced average velocity.

Generally described, each combustion chamber member 27 has a pair of side walls 38 and 3!, which are positioned to provide an aerodynamically optimum relation to the guide vanes 22 in the delivery end of the compressor section l l, the upstream ends of the combustion chamber members being aligned with the direction of flow of the air stream as it emerges from the compressor section ll. Such side walls, in the present instance, are shown as curved to straighten out the flow of the air stream, that is, to substantially eliminate itsperipheral component and to direct it substantially in an axial direction. Thus, the side wall 30 is shown as being externally conve: while the external surface of the side wall Si is concave. The

side walls

30 and 3! arealso divergent relative to each other in a downstream direction so as to provide increasing cross-sc tional' area within each combustion chamber member to permit proper how of the combustion gases. With this relative arrangement of the side walls, each space between the combustion chamber members has an aerodynamically optimum cross-sectional area distribution throughout its length, the shape, however, changing because 01' the increasingdivergence of the side walls rela- 'vo to each other and because of the increasing radial width of the annular passage 25 formed by the casings 2d and 25. The cro-sssectiona1 area of the chamber members 2'! are, of course, correlated to-the cross-sectionalareas of the passageway in the collector l3 and the annular passage 25 formed by the

casings

24 and 25. With such cross-sectional are-a distribution for the spaces between the combustion chamber members, the major portion of the air stream is free to flow therethrough at an aerodynamically optimum velocity, thereby decreasing the amount of retardation necessary on the major portion of the air stream.

The side walls 36 and 2H, at their upper ends, may be spaced from the downstream ends of the guide vanes 22 and may blend into each other in a rounded form, as indicated at 32 in Fig. 4. Thus, the air stream, as it passes beyond the ends of the guide vanes 22, is free to flow without turbulence on either side of each combustion chamber member.

Each combustion chamber member El also ineludes an inner wall 33 and an outer wall 34, these two walls being positioned so that they generally parallel the

casings

24 and 25. The two

walls

33 and 3 however, are spaced from the

casings

24 and 25 to permit a portion of the air 7 flow to pass between such walls and th casings, thereby providing an encasement or envelope of relatively cool air entirely surrounding each combustion chamber member to prevent dissipation of heat therefrom to the adjacent casings 2d and 25. In the present instance, each combustion chamber member 2? is support-ed in such position by means of the small foot 55 formed at the downstream end of the juncture of the side wall 3| and the inner wall 33 and by a flange 35 extending throughout the length of the combustion chamber member at the juncture of the side wall 3b with the inner wall 33. The flange and the foot 35 are rigidly secured to the inner casing 2%. At the outer side of each combustion chamber member El, there is a flange 3'3 (see Fig. 5) extending from the juncture of the side wall 36 and the outer wall 3 3 to provide the space between the outer wall 3 3 and the outer casing 2'5. The flange 3'! and the radial portion of the flange 36 have the further function of directing the flow of air in their respective areas toward an axial direction. The inner and outer walls 33 and 3d are generally arcuate in form since they substantially parallel the casings E i and 25. walls 30 and BI occupy a substantially radial position, so that the cross-sectional shape of each combustion chamber member, particularly at the downstream end, may be said to be segmental.

Fuel for combustion within each combustion chamber member 2'? may be supplied by a nozzle 4!) mounted externally on the outer shell 2'6 and projecting inwardly through the outer casing 25 and through an aperture ii in the outer wall 3d of the combustion chamber member. The air for combustion, as heretofore mentioned, is withdrawn from the flow of air in 25' which surrounds the respective combustion chamber members. To admit the air to the interionof each combustion chamber member, the concave side wall 3| may be provided with a plurality of perforations '42 (see Fig. 3), permitting the air to flow laterally from the main direction of the air stream into the combustion chamber. By utilizing a plurality of small perforations c2 and by withdrawing the air laterally, the velocity of the air flowing into the combustion chamber member is reduced sufficiently so that no difficulties are encountered within the combustion chamber of maintaining combustion therein. The diverging or flaring shape of each combustion member provides for the increase in volume of the combustion gases as combustion takes place, and such gases are permitted to flow outwardly in a relatively smooth stream through the open The side downstream end of each combustion chamber member. Since the air stream encases each combustion chamber member, it similarly en-cases the emerging combustion gases, thereby protecting the

casings

24 and 25 from the heat of such combustion gases downstream from the chamber members, and furthermore greatly facilitating the mixing of the relatively cool air stream with the hotter gases.

To further facilitate the mixing of the main portion of the air stream passing between the respective combustion chamber members with the combustion gases to attain the desired temperature distribution with a minimum flow energy or momentum loss, each concave side wall 3! is provided with means to thoroughly intermingle the air and combustion gases. Thus, a plurality of grooves open to the air stream in passage 25' and adapted to introduce the air into the emerging combustion gases in a layered formation is provided in the structure shown in Figs. 1 to 6. As clearly shown in Figs. 3 and 5, each concave wall 3| is corrugated, as at M, to provide rooves 45 into which the air from the main air stream enters. Such grooves extend from a point intermediate the ends of each concave wall 3! to the downstream end of such wall with a gradually increasing depth so that the air enters therein without turbulence and is introduced into the combustion gases in a series of spaced layers so that the two are thereby readily intermingled.

The fuel introduced in the respective combustion chamber members 21 by the fuel nozzles M3 is initially ignited by an electrical spark plug or the like (not shown). In order to avoid the necessity of providing a spark plug for each com bustion chamber, means is provided, in the present instance, for effecting ignition from adjacent chambers. With such means, one ignition device would be sufficient for a series of combustion chambers. In the present instance, twelve combustion chambers 21 are provided and only two ignition devices are utilized, such ignition devices being at diametrically opposite points. The means for effecting the ignition of the fuel in one chamber from combustion occurring in an adjacent chamber, in the present instance, comprises transfer tubes 46 extending across the spaces between the chamber members and connecting the side walls of adjacent combustion chamber members to provide communication therebetween. Preferably, such transfer tubes are located adjacent the upstream end of the combustion chamber members and extend transversely across the space between the adjoining members. When ignition takes place in one of the members, the pressure therein rises and creates a flow through the transfer member 45 to the adjoining chamber member and ignition is thereupon established in such adjoining member. Once the fuel is ignited in a chamber member, combustion continues to take place therein so long as the fuel is supplied thereto. With this arrangement, ignition takes place quickly in the entire series of combustion members so that, for practical purposes, two ignition plugs have been found su ficient to effect ignition of the fuel in all of the chambers.

The transfer tubes it not only function during the ignition of the fuel as described above, but also provide some definite advantages during op" eration of the turbine. Thus, it has been found that a pressure difference exists within each combustion member adjacent the respective sides thereof at the upstream end where the transfer tubestfi pen into thev chamber members. finch ressure: diiierence creates a flow oi hot eases through the transfer tube thus providin a means. for pr heating the f e as it. is introduce into the chamber members. In operation, i h been found that there i a higher pressure within each chamber member adjacent the point where the transfer tube extends from the wall 35} than there is directly opposite such point where the other transfer tube opens throu h the sid wall 3!. Considering two adjacent chamber members, there will. therefore. exist a pressure difference. on opposite ends of. ea h of the transf r tubes creating: a flow f. hot g se therethroueh. he gases b ing taken from the chamber member adjacent th sid wall at. and introduced into the next chamber member throu h h wall 31!. Su h pressure difference m y x st because of the non-symmetrical shape of each chamber member or it may be due to the aspirating action of the air enterin th perforations 42 abou th iacent end of the. transfer tube. Such air enterin through the perforations 42 would tend to reduce th pressure at th adjac nt en f th ransf r tube so that a flow therethrouah w ld be created.

'Ihe transfer tubes to, since they extend generally transversely across the space tween h combustion chamb r memb r 21, may fur h function as. guide van s to as ist in n rollin the direction of flow of; the major p rtion of th air stream between the chamber m mber Th y thus cooperate with th casinos 2 n 25 to ermine the radial comp nent of. h ow- In Figs. 7 and 8, combusti n h m r m mbers of somewhat modified. for ar h wn. Thus, each combustion chamber mber show in these two fi ures ompris s a outer w ll 5% an inner wall 55, and a pair of

side walls

52 and 53. The inner and outer walls 50' and Si as well as the

side walls

52 and 53, are shaped similarly to the correspondin walls i the preceding form, the

side walls

52 and 53 being similarly curved.

The principal difference between the two forms lies in the. construction of the upstream end of each combustion member. Thus, as shown in Figs. '7 and 8, the upstream end of the concave side wall 52 extends beyond the combustion chamber proper and is secured to one of the collector vanes 22, as indicated at 54, so, that it constitutes a continuation thereof. The wall 53 is also extended somewhat, as shown at 55, to provide for smooth flow of the air stream. The extended portions of the

walls

52 and 53 m y be connected by wall portions 56 extending from the inner and

outer walls

50 and 5! to provide a relatively deadspace in which the fuel supply means may be mounted. The chamber proper is separated from such space by a transverse wall 51 so that the interior of the c amber is com letely closed by wall structure at its upstream end.

Due to the direction of flow of the air stream, the concave walls 52, as is the case with the walls 3! in the other form, are at the high pressure of the air stream and may be called the high pressure walls. The walls 53 in the form shown in Figs. 7 and S, as well as the walls 3c in the form shown in the previous figures, may be said to constitute the low-pressure Side of the space between the adjacent members. Since the walls 52, as well as the walls 3| in the other form, are at the high-pressure side of the stream, the perforations provided to admit air to the interior of the combustion chamber are placed in such walls. In the form of combustion ohamber'shown in Figs. 7 and 8, a larger number of perforations,

indicated at Q. are .m'ovi ed. than heprev one form! In the form of F 7 and 8, t e perfora ions re located in an area extendi f om a po nt intermediate the ends of t cha b r su stantially to the extreme upstream end of the chamber proper, as is evident in Fig. 7. The perforations 60 thus extend entirely about the adjacent transfer tube 46. These perforations thus will admit primary air to support combustion within each chamber member. Additional primary air may be admitted through the upstream end of each combustion chamber by means of perforations 6% in the outer wall 56 and extending adjacent the low-pressure wall 53. Secondary air may be admitted to the interior of each chamber through larger perforations 62 provided in the downstream portion of each. side wall 52. The quantity of air admitted through the perforations 62 may be more than sufficient to insure complete combustion, so that the perforations 52 also function as a means for intermingling some of the air flow passing through the spaces between the respective chamber members with the combustion gases. Further mixing of the major portion of th air s eam passin through such spaces With the combustion gases mer n from the cham r mem ers. can be acplish d by ut n back the downstream edges of the

side walls

52 and 53 and the inner wall 5!, as indicated at 63.

With the. combined difiuser and combustion chamber section disclosed herein. the major portion of the air stream is permitted to flow in passage 25' between the respective combustion chamber members and between them and. the

casings

24 and 25. Thus, such major portion of the air stream may be maintained at an aerodynamically optimum velocity and need not be retarded to the extent that has heretofore been deemed necessary. While some reduction in the velocity of major portion may be found desirable, such retardation is not required because of the combustion within the combustion chamber members. However, the air withdrawn from the main air stream through the apertures 2 is so retarded that its velocity does not interfere with proper combustion within the chamber members. By virtue of the fact that the major portion of the air passes outside of the combustion chamber members, the heat thereof is not dissipated to the casings 2d and 25 so that no overheating thereof occurs. Such encasement effected by the air stream also facilitates the mixing of the relatively cool air with the combustion gases emerging from the chamber members. Further mixing is efiected by the layered formation in the air stream produced by the grooves 45 in the downstream end of each chamber member. A power stream is thus generated in which the air and combustion gases are thoroughly mixedand uniform temperature therein is attained before passing to the turbine section i5.

We claim:

1. A gas turbine comprising an air compressor section having uide vanes positioned generally radially in the delivery end thereof, and a combined diffuser and combustion chamber section having an annular air passage for receiving the air stream from the delivery end of said air compressor section, and a plurality Of hollow combustion chamber members mounted in said air passage in oircumferentially spaced relation to each other to permit flow of the air stream therebetween and having perforations to admit a portion of the air stream into said members to 9 support combustion therein, said members having radial walls that are fixed integrally with and form continuations of said vanes with the spaces between said walls of the respective members such as to maintain the flow at an aerodynamically optimum velocity.

2. A gas turbine comprising an air compressor section having an annular delivery passage provided with radially extending helical guide vanes, and a combined diffuser and combustion chamber section having an annular passage connected to said delivery passage for receiving the air stream from said delivery passage, and a plurality of hollow combustion chamber members located in said air passage in circumferentially spaced relation to each other to permit flow of the air stream therebetween and having perforations to admit a portion of the air stream into said members to support combustion therein, said members having arcuate inner and outer walls connected by radially extending walls, the latter having an integral connection with each of said vanes respectively and constituting continuations of said vanes, said continuations being shaped to eflect a change from a helical form into an axially extending form to change the air flow from helical to axial.

3. A gas turbine comprising an air compressor section having an annular delivery passage provided with radially extending helical guide vanes, and a combined diffuser and combustion chamber section having an annular air passage connected to said delivery passage for receiving the air stream from said delivery passage, and a plurality of hollow combustion chamber members located in said air passage in circumierentially spaced relation to each other to permit flow of the air stream therebetween and having perforations to admit a portion of the air stream into said members to support combustion therein, said members having arcuate inner and outer walls connected by radially extending walls, the latter having an integral connection with each of said vanes respectively and constituting continuations of said vanes, the radially extending walls of each member diverging from each other in a downstream direction to provide a flaring combustion chamber and progressively changing into axially extending form to change the air flow from helical to axial.

d. A gas turbine comprising an air compressor section, and a combustion chamber section comprising a pair of radially spaced annular casings providin an annular passage therebetween for receiving the air stream from the compressor section, said casings diverging relative to each other in a downstream direction and a plurality of hollow combustion chamber members situated in said passage and being disposed in circumferentially spaced relation to each other to permit flow of the air stream therebet v een, each member having arcuate inner and outer walls paralleling said casings and radially extending walis diverging from each other in a downstream direction to provide a flaring combustion chamber, each space between the members themselves and the annular casings having an aerodynamica-lly optimum distribution of cross-sectional area throughout its length to maintain the air therethrough at an aerodynamically optimum velocity.

5. A gas turbine comprising an air compressor section for delivering a helically moving air stream, and a combustion chamber section having an annular passage to receive the air stream, and a plurality of combustion chamber members located in said passage in circumierentially spaced relation to provide spaces for the air stream to pass therebetween, each of said members comprising a pair of inner and outer walls connected by a pair of walls extending substantially radially and extending downstream and being respectively concave and convex, the concave wall having apertures adjacent its upstream end for admitting air from the air stream into said member to support combustion therein at a reduced average velocity.

6. A gas turbine comprising an air compressor section, and a combustion chamber section having an annular passage for receiving the air stream from the compressor section, and a plurality of hollow combustion chamber members having radially disposed side walls, said members being mounted in said passage in circumferentially spaced relation to each other to provide radially positioned spaces for the air stream to pass between the members, said members being perforated to admit air from the air stream to support combustion therein and having their downstream ends open for discharge of the com bustion gases into the air stream, each of said members having a plurality of grooves on one of said radially disposed sides thereof, said grooves extending longitudinally and opening from the radially positioned spaces between said grooved sides and their adjacent members for introducing the air in a layered formation into the combustion gases to facilitate mixing thereof.

7. A gas turbine comprising an air compressor section for delivering a helically moving air stream, and a combustion chamber section having an annular passage to receive the air strean and a plurality of combustion chamber members located in said passage in a circumierentially spaced relation to provide spaces for the stream to pass therebetween, each of said mem bers comprising a pair of-inner and outer walls connected by a pair of walls extending substantially radially and being respectively concave and convex, the concave wall being corrugated inwardly adjacent its downstream end whereby air from the air stream is introduced in a layered formation into the combustion gases emerging from the member to facilitate mixing thereof.

8. A gas turbine comprising an air compressor section for delivering a helically moving air stream, and a combustion chamber section having an annular passage to receive the air stream, and a plurality of combustion chamber members located in said passage in circumferentially spaced relation to provide spaces for the air stream to pass therebetween, each of said members comprising a pair of inner and outer Walls connected by a pair of walls extending substantially radially and being respectively concave and convex, the concave wall having aperture adjacent its upstream end for admitting air from the air stream into said member to support combustion therein at a reduced average velocity and being bent inwardly of the member adjacent downstream end along a plurality of longitudinal lines to form a plurality of grooves increasing in depth in a downstream direction whereby air from the air stream is introduced in a layered formation into the combustion gases emerging from the member to facilitate mixing thereof.

9. A gas turbine comprising an air compressor section for delivering a helically moving air stream and a combustion chamber section comprising a pair or radially spaced annular casings providing an annular passage therebetween to receive the air stream, and a plurality of 1101?- low combustion chamber members mounted in said passage in spaced relation to each other to permit the air stream to pass therebetween, each member comprising a pair of arcuate Walls substantially paralleling said casings, a pair of substantially radial walls extending generally longitudinally of the. passage but diverging from each other in a downstream direction, said radial walls being curved to straighten the direction of air flow and with said arcuate walls giving the chamber member a segmental cross-sectional shape. and flanges projecting from edge portions of the member into engagement with said C359 ings to support the member in spaced relation to said casings.

10. A gas turbine comprising an air compressor section, and a combustion chamber section having a passage for receiving the air stream from said air. compressor section, and a plurality of hollow chamber members mountedin said passage in spaced relation to each other to permit a, major portion of the air stream to pass therebetween, and guide vanes positioned between the chamber members and extending from one chamber member to another to guide the flow of said major portion of the air stream, said guide vanes being hollow and providing communication between said chamber members to conduct hot gases from one member to another.

11. A gas turbine comprising: an air compressor section having guide vanes in the delivery end thereof, and a combustion chamber section having an annular passage for receiving the air strea'mfrom' said delivery end, and a plurality of hollow chamber members mounted in said passage in oircumferentiallyspaced relation to each other. and perforated to admit a portion of the air stream into said members with the remaining portion of the air stream flowing therebetween, each ofsaid members having a'pair of side walls for guiding the flow of said remaining portion with one of said side Walls secured at its upstream end to one of said vanes.

1 A gas turbine mp i i an air c mpressor section for delivering a helically moving air stream and having helical guide vanes in its delivery end, and a combustion chamber section having a ann a a sa or r ce v n ai a trea nd a. pl ra ty of ho w chambe m mhers mo nted in s id as e oi cum re t al y space r la io o a h er and. perforated to dmit a P QIl 0f th ai str m 11 Sa d members with the remaining portion of its air stream flow n thore et e e c of sa d m m ers a ins a Pai O s d a s curved to c ntr l th im tion, f flowof sa d remai in t one f Remittances one!) The following references are of record in the file of this patent:

UNITED STATES PATENTS