Abstract: A turbomachine including an annular combustion chamber, a centrifugal compressor, an annular diffuser enabling the flow of gas leaving the compressor to be diffused and directing this flow of gas towards the combustion chamber, and an outer casing surrounding the outside of the combustion chamber is disclosed. The diffuser includes an upstream portion oriented radially and presenting diffusion passages connected to the outlet from the compressor, an intermediate portion that is elbow-shaped, and a downstream portion having a series of circularly spaced-apart flow-straightening vanes. The flow stream in the downstream portion is delimited externally by the outer casing. The outer casing presents a shoulder against which the outer downstream edge of the intermediate portion comes into abutment.

Abstract: A turbomachine comprising: an annular combustion chamber (40); a centrifugal compressor (10); an annular diffuser (20) enabling the flow of gas leaving the compressor to be diffused and directing this flow of gas towards the combustion chamber, the diffuser comprising: an upstream portion (21) oriented radially and presenting diffusion passages (22) connected to the outlet from the compressor; an intermediate portion (24) that is elbow-shaped; and a downstream portion (25) having a series of circularly spaced-apart flow-straightening vanes (26); and an outer casing (32) surrounding the outside of the combustion chamber and the downstream portion; in which the flow stream in the downstream portion (25) is delimited externally by the outer casing (32).

Abstract: The invention applies to the field of turbomachines and relates to a novel device for injecting a mixture of air and fuel into a combustion chamber of a turbomachine. The injection device has symmetry of revolution about an axis (33) and comprises, arranged from upstream to downstream in the gas flow direction, radial swirl inducers (42, 43) of outside diameter D2, a bowl (30) spaced axially from the radial swirl inducers (42, 43), and a support ring (50) for supporting the injection device, which is arranged around the bowl (30). The bowl (30) has a cylindrical wall (32) extended by a flared wall (31), the flared wall (31) being provided with air intake holes (34).

Abstract: The invention provides a combustion chamber comprising a chamber wall disposed radially inside a casing, an igniter plug for igniting the air-fuel mixture, the plug being mounted on said casing and comprising a body with a free end that is disposed in an opening formed through said chamber wall with a large amount of clearance to accommodate relative displacement between said casing and said chamber wall, and a sealing device provided between said body and the perimeter of said opening, said sealing device comprising an annular plug-guide through which said body passes, the plug-guide being slidably mounted at the radially-outer end of an annular support whose base is secured to said perimeter, wherein the support is secured to the radially-outer portion of a chimney passing through said opening and presenting at its radially-inner end a collar bearing against the inside face of the chamber wall, and wherein a cooling circuit for said collar is provided.

Abstract: The invention provides a combustion chamber comprising a chamber wall disposed radially inside a casing, an igniter plug for igniting the air-fuel mixture, the plug being mounted on said casing and comprising a body with a free end that is disposed in an opening formed through said chamber wall with a large amount of clearance to accommodate relative displacement between said casing and said chamber wall, and a sealing device provided between said body and the perimeter of said opening, said sealing device comprising an annular plug-guide through which said body passes, the plug-guide being slidably mounted at the radially-outer end of an annular support whose base is secured to said perimeter, wherein the support is secured to the radially-outer portion of a chimney passing through said opening and presenting at its radially-inner end a collar bearing against the inside face of the chamber wall, and wherein a cooling circuit for said collar is provided.

Abstract: An offset annular combustion chamber for an airplane engine gas turbine, the chamber comprising a pilot head having a plurality of nozzle systems distributed on a pilot head chamber end wall interconnecting an inner longitudinally-extending side wall of the chamber to a pilot head outer longitudinally-extending side wall, and a take-off head that is radially and axially offset from the pilot head and comprising a plurality of nozzle systems distributed on a take-off head chamber end wall interconnecting the pilot head outer longitudinally-extending side wall and a take-off head outer longitudinally-extending side wall, the pilot head having at least N substantially identical nozzle systems with overall permeability PA adapted to lighting and to speeds close to idling, and the take-off head having at least 2N substantially identical nozzle systems of overall permeability PB, where PB is greater than or equal to PA, the permeability PA lying in the range 10% to 40% of the total air flow rate penetrating into th

Abstract: A pre-mixing injection system to feed a fuel/air mixture to a combustion zone in a turbojet engine combustion chamber is disclosed having a pre-mixing tube defining a convergent pre-mixing zone and a diverging intermediate zone between the fuel and air injection devices, and the combustion zone of the combustion chamber. The convergent pre-mixing zone has an inlet adjacent to the fuel injector and air swirlers to accept the fuel/air mixture into the pre-mixing tube. The pre-mixing zone converges in a direction from the inlet to an outlet which is in communication with the inlet of the divergent intermediate zone. The divergent intermediate zone has an outlet which is, in turn, in communication with the combustion zone of the turbojet engine combustion chamber. The divergent intermediate zone is defined by an inner wall and an outer wall spaced from the inner wall so as to define a generally frusto-conical chamber between them.

Abstract: A combustion chamber structure wherein the combustion chamber extends around a central, longitudinal axis and has primary oxidizer intake passageways whose positions along the central axis relative to an end of the combustion chamber are adjustable depending upon the operating conditions of the gas turbine engine. By controlling axial positions of the primary oxidizer intake passageways, the dwell time of the combustion gases and primary oxidizer inside the combustion zone of the chamber may also be controlled so as to increase the stability of the combustion, while at the same time minimizing the polluting emissions. The invention also encompasses the concept of adjusting the cross-sectional area of the primary oxidizer intake passageways as their positions along the central axis are adjusted. This enables a more accurate control of the volume of the primary oxidizer flow in addition to controlling the location of the flow.

Abstract: The combustion chamber according to the present invention utilizes a double-walled structure only in the converging portion of the combustion chamber. A hot wall is retained adjacent to, but spaced from a corresponding cold wall so as to provide a cooling space between them. An upstream portion of the hot wall is retained in a notch defined by the cold wall, while the downstream portions each have generally radially extending flanges. Studs pass through openings in the adjacent flanges to prevent any relative circumferential movement, while a clamp serves to attach the flanges to the inlet of a turbine. The clamp slidably retains the flanges therein so as to permit relative radial movement to accommodate any thermal expansion and contraction of the combustion chamber, solely by the appended claims.