阅读说明：本技术 包括具有分段孔的旋转封闭元件的定容燃烧系统 (Constant volume combustion system including a rotating closure element with segmented orifices ) 是由 M·雷科 P·J-B·梅奇 E·科奈特 G·梅库森 于 2018-06-20 设计创作，主要内容包括：本发明涉及一种用于涡轮机(10)的定容燃烧系统(1),包括：多个燃烧室(100),该多个燃烧室围绕限定轴向方向(DA)的轴线(XX’)以环形方式分布,每个燃烧室包括进气口(102)和排气口(103)；选择性封闭构件(200),该选择性封闭构件相对于燃烧室围绕轴线旋转地可移动,该选择性封闭构件包括套圈(210),该套圈(210)面向燃烧室的进气口和排气口,该套圈包含旨在与每个室的排气口协配的至少一个进气孔(2110、2111)和旨在与每个室的排气口协配的至少一个排气孔(2120、2121)。每个进气孔和每个排气孔被在每个孔中在轴向方向上延伸的至少一个部段分段。(The invention relates to a volumetric combustion system (1) for a turbomachine (10), comprising: a plurality of combustion chambers (100) distributed in an annular manner about an axis (XX') defining an axial Direction (DA), each combustion chamber comprising an intake port (102) and an exhaust port (103); a selective closing member (200) movable in rotation around an axis with respect to the combustion chamber, comprising a collar (210), the collar (210) facing the intake and exhaust ports of the combustion chamber, the collar containing at least one intake hole (2110, 2111) intended to cooperate with the exhaust port of each chamber and at least one exhaust hole (2120, 2121) intended to cooperate with the exhaust port of each chamber. Each intake aperture and each exhaust aperture is segmented by at least one segment extending in an axial direction in each aperture.)

1. A volumetric combustion system (1) for a turbomachine (10), the volumetric combustion system (1) comprising:

a plurality of combustion chambers (100) distributed in an annular manner about an axis (XX') defining an axial Direction (DA), each combustion chamber comprising an intake port (102) and an exhaust port (103),

a selective closing member (200), said selective closing member (200) being movable in rotation around said axis with respect to said combustion chamber, said selective closing member comprising a collar (210), said collar (210) facing said intake and exhaust ports of said combustion chamber, said collar containing on a first annular section (211) at least one intake hole (2110, 2111) intended to cooperate with said intake port of each of said combustion chambers during rotation of said selective closing member and on a second annular section (212) at least one exhaust hole (2120, 2121) intended to cooperate with said exhaust port of each of said combustion chambers during rotation of said selective closing member, each of said exhaust holes and each of said exhaust holes extending in a circumferential direction with respect to said axis for a determined length,

characterized in that each of said intake holes and each of said exhaust holes is segmented by at least one segment (2110a, 2111a, 2120a, 2121a) extending in each hole in said axial Direction (DA).

2. The system according to claim 1, wherein each section (2120a, 2121a) of each exhaust vent has, in a plane perpendicular to the axis (XX'), an aerodynamic profile extending between a leading edge (2120b, 2121b) and a trailing edge (2120c, 2121c), the leading edge being directed radially outwards with respect to the trailing edge.

3. The system of claim 2, wherein each vent (2120) is defined by a plurality of different sets of sections (2120a) ₁–2120a ₅) Uniformly segmented, wherein each segment (2120a) of the same group has the same angle of attack (α), the angle of attack of the segments of the same group varying in a strictly monotonic manner from one group of segments to another along the exhaust hole.

4. The system of claim 2, wherein each vent hole (2120) is uniformly segmented by a plurality of segments (2120a), each of the segments having a different angle of attack (α), the angle of attack of each of the segments varying in a strictly monotonic manner along the vent hole from one segment to another.

5. The system according to any one of claims 1 to 4, characterized in that each section (2110a, 2111a) of the intake aperture (2110, 2111) has, in a plane perpendicular to said axis (XX'), an aerodynamic profile extending between a leading edge (2110b, 2111b) and a trailing edge (2110c, 2111c), said leading edge being directed radially inwards with respect to said trailing edge.

6. The system according to any one of claims 1 to 5, further comprising a fixed intake guide (300), said fixed intake guide (300) being present on the inside of said collar (210) of said selective closure member (200) on the side of said first section (211) of said closure member, said intake guide comprising a central cylinder (301) radially extended by a disc (302), said cylinder and said disc forming a deflector configured to guide the air arriving at said intake guide in the direction of said intake opening (102) of said combustion chamber (100).

7. The system according to any one of claims 1 to 6, characterized in that said selective closing member (200) further comprises a wall (220) extending in a radial Direction (DR) from an inner surface (210a) of said ferrule (210) and separating said first annular section (211) and said second annular section (212) of said ferrule, said wall containing at least one bypass hole (223, 224) extending over an angular region outside the angular region in which said at least one intake hole (2110, 2111) and said at least one exhaust hole (2120, 2121) extend, said at least one bypass hole being angularly sectioned by at least one section (223a, 224a) extending in a radial direction with respect to said axis (XX').

8. The system according to claims 6 and 7, characterized in that said fixed intake guide (300) further comprises a plurality of holes (303), said plurality of holes (303) being able to cooperate with each bypass hole (223, 224) of said wall (220) of said selective closing member (200).

9. The system according to any one of claims 1 to 8, characterized in that each combustion chamber (100) is delimited by a casing (101), a closed rear bottom (100b) forming a single piece with the casing, and a cylindrical ring (110) attached to its outer surface (112), the cylindrical ring (110) forming a front bottom (100a) of each combustion chamber, the cylindrical ring comprising a first series of holes (113) each forming the intake opening (102) of the combustion chamber (100), and a second series of holes (114) each forming the exhaust opening (103) of the combustion chamber,

the system also comprises a fixed exhaust manifold (400) extending in an annular manner along the second annular section (212) of the collar (210) of the selective closing member (200) inside the collar, the exhaust manifold comprising a plurality of separate compartments (410), each of which is present at the level of the exhaust port (103) of the combustion chamber (100).

10. The system according to claim 9, wherein each hole of the second series of holes (114) is circumferentially separated from its adjacent hole by a non-zero distance (e), the venting holes (2120, 2121) comprising a plurality of sections (2120a, 2121a) uniformly distributed in the holes and separated from each other by a distance (P) less than or equal to the distance (e) separating two holes of the second series of holes.

11. A system according to any one of claims 1 to 10, comprising ten combustion chambers (100) distributed in an annular manner around said axis (XX ') and comprising a plurality of annular chambers (c) arranged in a plurality of annular chambers (c) arranged around said axis (XX') ₁–100 ₁₀) -the collar (210) of the selective closing member (200) comprises two diametrically opposite inlet holes (2110, 2111) on the first annular section (211) and two diametrically opposite outlet holes (2120, 2121) on the second annular section (212) of the collar, -the wall (220) of the selective closing member comprises two bypass holes (223, 224), the two bypass holes (223, 224) extending over an angular area lying outside the angular area over which the two inlet holes and the two outlet holes extend.

12. The system according to any one of claims 1 to 11, wherein the selective closing member (200) is made of one of the following materials: metallic materials, ceramic matrix composites, and eutectic ceramic materials.

13. A turbomachine (10), the turbomachine (10) comprising an axial or centrifugal compressor and an axial or radial turbine, the turbomachine further comprising a combustion system (1) as claimed in any one of claims 1 to 12, the combustion system being present between the compressor and the turbine.

14. An aircraft comprising at least one turboprop including the turbine of claim 13.

Technical Field

The present invention relates to the field of aircraft turbine combustors of the constant volume combustion type. The invention is applicable to any type of turbomachine, in particular jet engines, turboprop engines and turbomachines with non-ducted fans, also known as "open rotors".

Background

Conventional aircraft turbines comprise one or more combustion chambers in a known manner. Such a combustion chamber is supplied with pressurized air by the compressor module and it contains fuel injectors capable of injecting fuel into the intake air flow to burn it and thus cause the emission of hot gases for driving the turbine, which in turn drives the compressor module and which can also drive the fan of the turbine.

In such combustion chambers, the fuel flow rate is continuous and the combustion operates according to the so-called brayton cycle (brayton cycle), i.e. according to a constant pressure combustion or "CPC" cycle. However, in order to obtain a certain consumption gain, it has been envisaged to replace the combustion chambers operating according to the brayton cycle with a plurality of combustion chambers operating according to the Humphrey cycle, i.e. according to the constant volume combustion or "CVC" cycle.

Document WO2016/120551 discloses a constant volume combustion module comprising combustion chambers arranged around an axis, each combustion chamber comprising a compressed gas inlet and a combustion gas outlet, and a rotary intake/exhaust valve. Each intake/exhaust port is configured to be opened or closed by rotating the intake/exhaust valve.

In order to use this type of volumetric combustion module in high power gas turbines, it is desirable to have a significant number of combustors (e.g., at least three). In some cases, several chambers must be synchronized in operation, i.e. in the same state at the same time. In this case, the rotary valve may take the form of a cylinder provided with a circumferentially extending bore of predetermined length which is capable of co-operating with the inlet and outlet ports of each chamber. Such a rotary valve therefore has an orifice which can have a considerable size in relation to the number of combustion chambers to be synchronized and/or the size of said combustion chambers. Furthermore, such a valve may comprise several of these holes on the same annular section of the valve. These holes therefore greatly reduce the stiffness of the valve and therefore the mechanical resistance when the valve is rotationally driven in a gas turbine and its reliability.

Disclosure of Invention

The object of the present invention is therefore to eliminate said drawbacks by proposing a volumetric combustion system for a turbomachine, comprising:

a plurality of combustion chambers distributed in an annular manner about an axis defining an axial direction, each combustion chamber including an intake port and an exhaust port,

a selective closing member movable in rotation about an axis with respect to the combustion chamber, the selective closing member comprising a collar facing the intake and exhaust ports of the combustion chamber, the collar comprising on a first annular section at least one intake hole intended to cooperate with the intake port of each combustion chamber during rotation of the selective closing member, and on a second annular section at least one exhaust hole intended to cooperate with the exhaust port of each combustion chamber during rotation of the selective closing member, each intake hole and each exhaust hole extending in a circumferential direction of a determined length with respect to the axis.

According to the invention, each inlet opening and each outlet opening is segmented by at least one segment extending in the axial direction in each opening. Thus, due to the presence of a section in each hole, the hole is reinforced and thus the stiffness of the selective closing member is increased.

In an exemplary embodiment, each section extends only in the wall thickness of the collar of the selective closure member. In other words, these sections do not protrude beyond the wall of the ferrule. Still alternatively, each segment has a length measured in a radial direction (relative to the axial direction) that is less than or equal to a wall thickness of the ferrule of the selective closure member (also measured in the radial direction). This feature allows for better integration with a volumetric combustor for a turbine.

In an exemplary embodiment, the air intake and exhaust apertures may be present simultaneously on at least one circumferential section of the ferrule (i.e., side-by-side on a section of the ferrule). When said circumferential section passes opposite to the combustion chamber, the circumferential section of the collar on which the inlet and outlet holes are simultaneously present (i.e. a certain angular section of the collar) corresponds to a scavenging phase (in which the air from the compressor passes through the combustion chamber to empty it and to refill it), as will be explained later.

In an exemplary embodiment, each section of each exhaust hole may have an aerodynamic profile in a plane perpendicular to the axis extending between a leading edge and a trailing edge, the leading edge being directed radially outward relative to the trailing edge. Due to this arrangement, aerodynamic losses due to the presence of sections in each exhaust aperture may be reduced. In particular, in the case of an exhaust aperture, the aerodynamic profile is oriented according to the direction of the air flow passing through the aperture, i.e. radially from the outside to the inside of the selective closing member. In order to reduce the influence on the air flow of the individual segments, at least one segment of the exhaust aperture may have an aerodynamic profile as defined above.

When the selective closure member is rotationally driven, different sections of its exhaust vent do not "see" the same type of airflow. In particular, the section that would be on one side of the exhaust port would always see a flow corresponding to the exhaust phase of the combustion chamber, while the section on the other side of the exhaust port would always see a flow corresponding to the exhaust end phase or scavenging phase of the combustion chamber. Thus, the incidence of the airflow on the aerodynamic profile of the segment varies from one edge of the exhaust aperture to the other, and in particular from high incidence (high pressure and temperature) to lower incidence (low pressure and temperature).

In order to take account of this variation in the incidence of the gas flow as a function of the circumferential position of each segment in the hole, it is advantageous if each discharge orifice is uniformly segmented by a plurality of different segments, each segment having an angle of attack which varies in a strictly monotonic manner along the discharge orifice from one segment to the other. The angle of attack may be defined as the angle of the normal to the surface of a segment taken at the leading edge of that segment to the normal to the outer surface of the collar of the selective closure member taken at the leading edge of the segment in question.

As a variant, each vent hole may be uniformly segmented by a plurality of different groups of segments, wherein each segment of a same group has the same angle of attack, the angle of attack of the segments of a same group varying in a strictly monotonic manner along the vent hole from one group of segments to another. This design is easier to implement than previous designs, in particular because it reduces the number of different types of sections that have to be provided for it.

Although the incident variation of the air flow is smaller than in the case of the exhaust, the previously advantageous arrangement can be applied to each intake hole in a similar manner.

In an exemplary embodiment, each section of the air intake aperture has an aerodynamic profile in a plane perpendicular to the axis extending between a leading edge and a trailing edge, the leading edge being directed radially outwardly relative to the trailing edge. Due to this arrangement, aerodynamic losses due to the presence of a section in each air inlet aperture can be reduced. In particular, in the case of an air intake aperture, the aerodynamic profile is oriented according to the direction of the air flow passing through the aperture, i.e. radially from the inside to the outside of the selective closure member. In order to reduce the influence on the air flow of the individual sections, at least one section of the air inlet opening can have an aerodynamic profile as defined above.

In an exemplary embodiment, the combustion system may further comprise a stationary intake guide present on the inside of the collar of the selective closure member on the side of the first section of said closure member, the intake guide comprising a central cylinder radially extending from a disc, the cylinder and disc forming a deflector configured to direct air arriving at the intake guide in the direction of the intake opening of the combustion chamber. Due to the intake guide, the introduction of fresh air flow into each combustion chamber is optimized.

In an exemplary embodiment, the selective closure member may further comprise a wall extending in a radial direction from the inner surface of the collar and separating the first and second annular sections of the collar, said wall containing at least one bypass hole extending over an angular region outside the angular region over which the at least one inlet hole and the at least one exhaust hole extend, said at least one bypass hole being angularly segmented by at least one section extending in a radial direction with respect to the axis. Due to the presence of the one or more bypass holes on the selective closing member, there may be a constant air flow in the combustion module, which air flow bypasses the combustion chamber. As a result, with a constant air flow between the buffer volume upstream of the combustion system (output of the compressor) and the output of the combustion system (supply of the turbine), the fluctuations in flow rate and pressure in the combustion system are reduced, which makes it possible to improve the fluidity of the load present on the compressor upstream of the combustion system and the efficiency of the turbine placed downstream of the combustion system. Furthermore, one or more bypass holes are present on the rotating components of the combustion system, the air flow being regularly distributed over different parts of the combustion system, which makes it possible to purge these parts of combustion gases and regularly cool them.

In this case, and when the combustion system comprises a fixed intake guide as defined above, the fixed intake guide may further comprise a plurality of holes able to cooperate with each bypass hole of the wall of the selective closure member.

In an exemplary embodiment, each combustion chamber may be defined by a housing, a closed rear bottom forming a single piece with the housing, and a cylindrical ring attached to an outer surface of the housing, the cylindrical ring forming a front bottom of each combustion chamber, the cylindrical ring comprising: the system further comprises a stationary exhaust manifold extending in an annular manner inside the collar of the selective closing member along the second section of said collar, the exhaust manifold comprising a plurality of separate compartments, each separate compartment being present at the level of the exhaust port of the combustion chamber. This design facilitates the manufacture of the combustion chamber and its annular distribution around the axis of the combustion system. Due to such a divided exhaust manifold, the exhaust gas of the combustion chamber is independent of the other combustion chambers, which makes it possible to reduce the return of pressurized hot gas from one chamber towards the other, in particular during the scavenging phase of the combustion chamber.

In this case, each hole of the second series of holes may be circumferentially separated from its adjacent holes by a non-zero distance, the exhaust hole comprising a plurality of segments evenly distributed in said holes and mutually separated by a distance less than or equal to the distance separating two holes of the second series of holes. By this arrangement the possibility of hot gas returning from one chamber towards the other is further reduced, in particular during the scavenging phase of the combustion chamber. In particular, the segmentation of the vent holes in this way makes it possible to prevent the gas from crossing from one chamber to the other by passing through the thickness of the vent holes.

The combustion system according to the invention may comprise ten combustion chambers distributed in an annular manner around an axis, the collar of the selective closing member comprising two diametrically opposite intake ports on a first annular section of said collar and two diametrically opposite exhaust ports on a second annular section of said collar, the wall of the selective closing member comprising two bypass holes extending over an angular region outside the angular region over which the two intake ports and the two exhaust ports extend.

Preferably, the selective closing member may be made of one of the following materials: metallic materials, ceramic matrix composites, and eutectic ceramic materials.

Another subject of the invention is a turbomachine comprising an axial or centrifugal compressor and an axial or radial turbine, and comprising a combustion system according to the invention, which is present between the compressor and the turbine.

Hair brushA further subject of the invention is an aircraft comprising at least one turboprop comprising a turbomachine according to the invention. Drawings

Further features and advantages of the invention will become apparent from the description given below, with reference to the accompanying drawings, which illustrate exemplary embodiments of the invention, without any limiting features. In the drawings:

FIG. 1 is a schematic longitudinal section of a turbomachine comprising a combustion system according to an embodiment of the invention,

figure 2A is an exploded perspective view of the combustion system of figure 1,

figure 2B is an enlarged view at the level of reference IIB of figure 2A,

figures 3A and 3B are schematic perspective views of an alternative closure member of the combustion system of figure 1,

FIGS. 4 and 5 are respectively cross-sectional views along a plane perpendicular to the axis XX' of the three sections of the inlet aperture and of the three sections of the outlet aperture,

FIG. 6 is a section along a plane perpendicular to the axis XX' of the venting orifice,

figure 7 shows different angles of attack of the grouped sections of the vent holes as shown in figure 6,

figures 8A to 8D are perspective views of the exhaust manifold of the combustion system of figure 1,

FIG. 9 is a schematic perspective view of the combustion chamber and the selective closing member of the combustion system of FIG. 1,

FIG. 10 is a developed schematic view showing the relative positions of the intake and exhaust ports of the selective closure member, the intake and exhaust ports of several combustion chambers in the position of the combustion system shown in FIG. 9,

FIG. 11 is a schematic representation of a developed section of the exhaust levels of the four combustion chambers in the position of the combustion system shown in FIG. 9,

fig. 12 is a table showing the different phases of the hanflei cycle of each combustion chamber according to the angular or rotational position of the closing member of the combustion system of fig. 1.

Detailed Description

The invention is generally applicable to turbomachines comprising axial or centrifugal compressors and axial or radial turbines.

Fig. 1, 2A to 2B show a combustion system 1 according to an embodiment of the invention. In the example described here and as shown in fig. 1, the combustion system 1 is incorporated into a turbine or turbine shaft 10 of a turboprop engine, the combustion system being placed in the turbine shaft downstream of an axial centrifugal compressor 11 and upstream of an axial turbine 12, the compressor 11 and the turbine 12 being joined together by a shaft system 13. The turbine 12 comprises a movable wheel 120, which is coupled at its centre to the shaft system 13 and comprises at its radial ends a plurality of blades 121.

The combustion system 1 comprises a plurality of combustion chambers, in the embodiment described herein 10 combustion chambers 100, numbered 100 in fig. 2A ₁To 100 ₁₀Distributed in an annular manner around an axis XX' defining an axial direction DA. Each combustion chamber 100 is delimited by a casing 101, here substantially parallelepiped-shaped, a closed rear bottom 101b, which forms a single part with the casing 101, and a cylindrical ring 110, to the outer surface 112 of which the casing 101 is attached, for example by welding, brazing, mechanical coupling (screw-nut) or gluing, when the casing 101 and the cylindrical ring 110 are made of metallic material. The cylindrical ring 110 and the casing 101 may also be made of a Ceramic Matrix Composite (CMC) material, i.e. a material formed by reinforcements made of carbon fibers or ceramic and densified by an at least partial ceramic matrix.

The cylindrical ring 110 forms a front bottom 101a of each combustion chamber, which front bottom 101a is positioned as close as possible to the axis XX' in the radial direction DR in the opposite direction to the rear bottom 101 b. The cylindrical ring 110 includes a first series of apertures 113 and a second series of apertures 114, each first series of apertures 113 forming an intake port 102 of the combustion chamber 100 and each second series of apertures 114 forming an exhaust port 103 of the combustion chamber 100 (fig. 2B). The front bottom 101a of each combustion chamber 100 also contains an intake port 102 and an exhaust port 103. The inner surface 111 of the cylindrical ring 110 containing the intake and exhaust ports of each combustion chamber is intended to be placed facing the collar of the selective closure member described in detail below. The casing 101 of the combustion chamber extends in a radial direction DR from the outer surface 112 of the ring 110. In the example described herein, each combustion chamber 100 is also equipped with a fuel injector 104, where the fuel injector 104 is placed on the aft bottom 101b of each combustion chamber 100. The spraying can also be carried out by means of a spraying wheel (not shown in fig. 2A and 2B). Combustion may be initiated in a known manner by a spark igniter (spark plug), or by a hot gas igniter (not shown in fig. 2A and 2B). Combustion can also be initiated by exhaust gas recirculation or EGR, as in diesel engines, if conditions permit.

The combustion system 1 further comprises a selective closing member 200, which selective closing member 200 is rotatably movable with respect to the combustion chamber 100 about an axis XX'. The selective closing member 200 comprises a collar 210, the collar 210 facing the inlet 102 and the outlet 103 of the combustion chamber 100. The ferrule 210 is divided into a first annular section 211 and a second annular section 212, each section extending over the entire circumference of the ferrule 210 (fig. 3A and 3B). The first annular section 211 contains at least one intake hole for cooperation with the intake port 102 of each combustion chamber 100 during rotation of the selective closure member 200. In the example described herein, the first annular section 211 contains two air intake holes 2110 and 2111 angularly offset by 180 ° along the first section. The second annular section 212 contains at least one exhaust hole for cooperation with the exhaust port 103 of each combustion chamber 100 when the selective closing member 200 rotates. In the example described herein, the second annular section 212 contains two air inlet holes 2120 and 2121 angularly offset by 180 ° along the second end. The beginning of each intake hole 2110, 2111 is angularly aligned with the beginning of each exhaust hole 2120, 2121, respectively, which extends over a greater circumferential length than the intake hole. The selective closing member may be made of a metallic material or of a CMC material.

According to the invention, each intake hole 2110, 2111 and each exhaust hole 2120, 2121 is segmented by at least one segment extending in the axial direction DA in each hole. In particular, the first intake holes 2110 and the second intake holes 2111 are respectively sectioned by a plurality of sections 2110a and 2111a uniformly distributed circumferentially (with respect to the axis XX') in said holes. The first and second exhaust holes 2120 and 2121 are respectively segmented by a plurality of segments 2120a and 2121a which are evenly distributed circumferentially in the holes. These sections make it possible to enhance the mechanical resistance of the selective closing member 200.

According to an advantageous arrangement of the invention, the sections 2110a, 2111a, 2120a and 2121a have an aerodynamic profile extending between the leading edge and the trailing edge in a plane perpendicular to the axis XX'. This configuration makes it possible to reduce the aerodynamic disturbances due to the sections present in the intake and exhaust apertures.

As shown in FIG. 4, the section 2110a of the first intake bore 2110 has an aerodynamic profile in a plane perpendicular to the direction DA extending between a leading edge 2110b and a trailing edge 2110c, the leading edge 2110b being directed radially inward (i.e., toward the axis XX') so as to face the intake air flow FA in the combustion chamber 100 when the combustion chamber is in the scavenging stage.

As shown in fig. 5, the section 2120a of the first exhaust hole 2120 has an aerodynamic profile in a plane perpendicular to the direction DA extending between a leading edge 2120b and a trailing edge 2120c, the leading edge 2110b being directed radially outward (i.e., directed opposite to the axis XX') so as to face the exhaust flow FE in the combustion chamber 100 when the combustion chamber is in an exhaust or scavenging phase.

According to an advantageous arrangement of the invention, shown in figures 6 and 7, each exhaust 2120 is made up of a plurality of different grouped sections 2120a ₁、20120a ₂、20120a ₃、2120a ₄、2120a ₅Uniformly segmented, wherein each segment 2120a of a set of segments has the same angle of attack, which varies in a strictly monotonic manner from one set of segments to another along the exhaust aperture 2120. In particular, group 2120a ₁Is strictly smaller than the group 20120a ₂Until the last group 20120a of segments ₅. This arrangement makes it possible to take into account the variation of the incidence of the gas flow at the exhaust between the different phases, in order to further reduce the influence of the sections present in the gas flow.

As shown in FIG. 7, the angle of attack α corresponds to the angle formed by the normal to the leading edge 2120b of the segments 2120a and the normal Z to the outer surface 210b of the ferrule 210 taken at the level of the leading edge 2120b of each segment 2120a the segments 2120a superimposed at the level of their leading edges 2120b are shown on FIG. 7 to compare their angles of attack it can be seen that the angle of attack α 1 of the ganged segments located opposite the air intake holes 2110 is greater than the angle of attack α 5 of the ganged segments on one side of the air intake holes (only two extreme angles are shown for clarity).

This monotonic change in angle of attack adjusts to the direction of rotation of the closure member 200 and the position of the inlet bore 2110 in the turbine 10. in particular, as is the case at the beginning of the exhaust phase, it can be ensured that the section 2120b "seeing" the gas flow with a high angle of incidence has a considerable angle of attack α. conversely, for example during scavenging and at the end of scavenging, the section 2120b, which will be arranged in the flow with a lower angle of incidence, can have a smaller angle of attack α.

In a variant not shown, each segment may have an angle of attack different from its neighbouring segments. Of course, all the contents already described above for the first exhaust holes 2120 may be applied to the second exhaust holes 2121 in the same manner. It should be noted that sections 2110a and 2111a of the intake ports 2110 and 2111 may be similarly arranged, but the effect of the sections becomes smaller because the change in intake air flow is much smaller than the change in exhaust gas flow.

The combustion system 1 further comprises a stationary intake guide 300, which intake guide 300 is present on the inner side of the collar 210 of the closure member 200 on one side of the first section 211 of the closure member (fig. 2A). The intake guide 300 further comprises a central cylinder 301 radially extended by a disc 302, the cylinder 301 and the disc 302 forming a deflector for the intake air, for example from the compressor 11 arranged upstream of the combustion system. The deflector thus formed makes it possible to guide the air arriving on the intake guide in the direction of the intake opening of the combustion chamber. Here, the exhaust guide 300 includes a plurality of holes 303 existing on the tray 302, the function of which is defined below. According to a variant embodiment of the intake guide, the latter does not comprise any holes 303, the disc 302, which stops below the bypass holes 223 and 224, being present on the selective closing member 200. The intake guide 300 may be made of a metal material or a CMC material.

In the example described herein, the combustion system 1 also includes a stationary exhaust manifold 400 (FIG. 1) having an annular shape. The exhaust manifold 400 extends on and along the side of the second section 212 of the ferrule partially inside the ferrule 210 of the selective closure member (fig. 8D).

As shown in fig. 8A to 8D, the exhaust manifold 400 comprises an inner collar 401 and an outer collar 402, between which a plurality of separate compartments 410 are distributed in an angled manner, each compartment being placed facing the exhaust port 103 of the combustion chamber 100 (fig. 8D). More precisely, each divided compartment 410 is delimited by two radial walls or spacers 411 extending in the radial direction DR between the inner collar 401 and the outer collar 402, between which spacers 411 sections of the inner collar 401 and of the outer collar 402 are present, which form the inner and outer spacers of the compartment 410, respectively. The outer collar 402 contains a plurality of holes 413, each hole corresponding to the first hole of each of the partitioned compartments 410. Each first hole 413 is present facing the exhaust port 103 of the combustion chamber 100, the length l of the first hole 413 ₄₁₃(FIG. 8A) is greater than or equal to the length l of the exhaust port 103 ₁₀₃(FIG. 8D). In the example described herein, since the combustion system includes 10 combustion chambers, the exhaust manifold 400 includes 10 compartments 410. The spacer 411 also mutually defines a first aperture 413 and a second aperture 414 downstream of the exhaust port 103. The terms "upstream" and "downstream" are used herein with reference to the flow direction of the airflow in the combustion system (arrow F in fig. 1). The second apertures 414 define an exhaust direction of the combustion gases injected from each exhaust port 103 when the combustion chamber 100 is in an exhaust phase. More precisely, the combustion gases discharged by the second holes 414 of the compartment 410 of the exhaust manifold 400 open downstream of the combustion system in a direction substantially parallel to the axis XX' and with a volume fraction independent of the other volume fractions (fraction de volumes) into which the holes 414 of the other compartments 410 open. When a turbine, such as the turbine 12 shown in fig. 1, is present downstream of the constant volume combustion system 1, which systematically receives combustion gases from the combustion chamber 100, the compartment 410 prevents the gas flow from returning into the combustion chamber during the scavenging phase.

In the example described here, the spacer 411 extends in the axial direction DA over almost the entire width of the outer surface of the inner ferrule 401 and the inner surface of the outer ferrule 402.

Further, in the example described herein and not by way of limitation, the tip 4110 of each spacer has an aerodynamic profile that is curved with respect to the axial direction XX ', which enables deflection of the combustion gases from the combustion chamber 100 in a direction that is not parallel to the axis XX'. The angle of deflection of the direction of the combustion gas is defined by the curvature of the tip 4110 of the spacer 411. This may be determined in particular in order to optimize the efficiency of the combustion system with respect to the turbine placed downstream thereof. In the combustion system of the present invention, the spacer 411 may also have a straight line profile between both ends thereof.

In the still here described and non-limiting example, the exhaust manifold 400 also comprises a plurality of fixed vanes 420 present downstream of the compartment 410, one or more vanes (here two) being evenly distributed between the spacers 411. The fixed vanes 420 each have an aerodynamic profile 421 curved with respect to the axial direction XX', the profile 421 of the vane 420 preferably having a curvature (direction and angle of curvature) similar to the curvature of the tip 4110 of the spacer 411.

The fixed vane 420 having the spacer 411 functions as a nozzle guide vane for gas from the combustion system. The exhaust manifold may be made of a metallic material or a CMC material.

According to an advantageous arrangement of the invention, the selective closing member 200 further comprises a wall 220 extending in a radial direction DR (i.e. perpendicular to the axis XX') from the inner surface 210A of the ferrule, the wall 220 separating the first annular section 211 and the second annular section 212 of the ferrule 210 (fig. 3A and 3B). The wall 220 has a circular central aperture 221, the edge of the circular central aperture 221 being defined by a cylinder 222. The cylinder 222 is mounted on the upstream side of a first roller bearing 230 that forms a single component with the cylinder 220, the first bearing 230 being equipped with a toothed wheel 231 (fig. 2A) that is in contact with a pinion 232 mounted on a drive shaft 233. The barrel 222 includes a second roller bearing 240 on the downstream side. Here, the rotational setting of the closing member is controlled by a drive shaft 233 coupled to an engine (not shown in fig. 2A) external to the combustion system, which shaft 233 traverses the intake guide 300.

According to an advantageous arrangement of the invention, the selective closing member comprises one or more bypass holes. More precisely, in the embodiment described herein, the wall 220 of the closure member 200 comprises a first bypass orifice 223 and a second bypass orifice 224, which are arranged in a diametrically opposite manner on the wall 220 (fig. 3A and 3B). Each bypass aperture extends over an angular region that is outside the angular region over which one or more inlet and exhaust apertures extend. In the example described herein, the first bypass hole 223 and the second bypass hole 224 extend over angular regions that extend between the angular regions over which the first intake holes 2110 and the first exhaust holes 2120 extend on the one hand and the second intake holes 2111 and the second exhaust holes 2121 extend on the other hand, respectively. To strengthen the wall 220 and the selective closing member 200, each bypass hole 223 and 224 may be segmented by a plurality of segments 223A and 224a, respectively (fig. 3A and 3B). The sections 223a and 224a extend in the radial direction DR relative to the axis XX' and angularly segment the bypass holes 223a and 223 b. In the example shown, the sections 223a and 224a are angularly distributed in a uniform manner in the respective bypass holes 223 and 224.

The combustion chamber 100, the selective closing member 200, the intake guide 300 and the exhaust manifold 400 are mounted inside a casing 500 formed by two parts 501 and 502.

The selective closing member 200 is the only rotationally movable member in the combustion system 1. Upon rotation thereof, the selective closing member 200 will selectively open and close the intake port 102 and the exhaust port 103 of each combustion chamber, so as to achieve constant volume combustion, i.e., scavenging time of intake and combustion gases containing combustion time, exhaust time, and fresh air, according to the hanflei cycle. More precisely, as shown in fig. 5 and 6, some of the combustion chambers 100 are in the scavenging stage, others are in the exhaust stage, and others are again in the combustion stage, depending on the rotation angle of the selective closing member, and on the position of the intake and exhaust holes present on the collar of the closing member 200. FIG. 6 shows the beginning of the first inlet 2111 and outlet 2121 holes and the chamber 100 as they exist on the collar 210 of the closure member 200 ₁ Inlet port 102 and exhaustWhen the start of the port 103 is aligned, the chamber 100 ₁To 100 ₅And (3) a stage of (a). Here, the aperture 2111 is at length l ₂₁₁₀Extends upwardly, covering a first chamber, here chamber 100 ₁And a second chamber adjacent to the first chamber, here chamber 100 ₂Of the air inlet. The vent 2121 being of length l ₂₁₂₁Extending upwards, covering 3 successive combustion chambers, here chambers 100 ₁、100 ₂、100 ₃. The beginning of the intake ports 2111 and the exhaust ports 2121 are aligned in the axial direction DA on the collar 210.

In the angular or rotational position of the collar 210 shown in fig. 10 and 11, the combustion chamber 100 ₁And 100 ₂In the scavenging stage, because the intake ports 2111 and the exhaust ports 2121 are fully opened to the combustion chamber 100 ₁And 100 ₂An inlet 102 and an outlet 103. Chamber 100 ₃In the exhaust phase, its inlet port 102 is fully closed by the collar 210, while its outlet port 103 is fully opened by the exhaust hole 2121. Finally, the combustion chamber 100 ₄And 100 ₅Are in the combustion phase and their intake and exhaust ports are fully closed by the collar 210.

According to an advantageous arrangement of the invention, shown in particular in fig. 10 and 11, the exhaust holes 103 are separated from each other by a non-zero distance eAnd the sections 2121a of the second discharge hole 2121 are separated from each other by a distance less than or equal to eE.g., less than or equal to 0.5 e. In the example shown, P is 0.5 e. FIG. 11 shows the combustion system 1 in a combustion chamber 100 ₁₀、100 ₁、100 ₂、100 ₃Is shown in the expanded cross-sectional view (in a plane perpendicular to the direction DA) at the level of the exhaust port 103. The figure allows a better understanding of the advantages of such an arrangement. The exhaust manifold 400 is seen divided by radial spacers 411, as well as the exhaust ports 103 facing the compartments 410 of the manifold 400. As shown in fig. 9 and 10, the combustion chamber 100 ₁₀At the beginning of the combustion phase, the combustion chamber 100 ₁And 100 ₂In the scavenging stage, and the combustion chamber 100 ₃In the exhaust phase. The closure member 200 has a non-zero thickness through which gas can pass from one chamber to the other. Since the exhaust hole 2121 is sectioned by the section 2121a, it is furtherReduce the pressure from the chamber 100 ₃Towards the chamber 100 due to overpressure ₂The risk of deflection.

FIG. 12 is a view illustrating each combustion chamber 100 according to the angular or rotational position θ of the closure member 200 ₁To 100 ₁₀Table of different phases of the hanflei cycle.