Abstract: A method of supplying fuel to a combustion chamber of a turbojet engine having a low power head with a plurality of low power fuel injectors and a high power head having a plurality of high power fuel injectors is disclosed in which fuel is supplied to the plurality of low power fuel injectors during low power operation of the engine, fuel is supplied to a first fuel circuit in the plurality of high power fuel injectors during high power operation of the turbojet engine and fuel is also supplied to a second fuel circuit in the plurality of high power fuel injectors during low power operation of the turbojet engine, the second fuel circuit being separate from the first fuel circuit. This method of supplying fuel to the dual head combustion chamber optimizes operation of the combustion chamber in all modes of engine operation.

Abstract: A wall structure for a wall bounding a combustion chamber of a gas turbine engine is disclosed having a first wall with an inner surface facing towards the interior of the combustion chamber and an outer surface facing away from the interior of the combustion chamber such that the inner surface forms a boundary of the combustion chamber and the outer surface has a surface roughness to prevent the formation of a fluid flow cooling layer which would cool the outer surface. The invention also has a second wall spaced from the outer surface of the first wall in a direction away from the interior of the combustion chamber so as to define a cooling fluid circulatory space between the first and second walls. A plurality of first perforations extend through the first wall in communication with the cooling fluid circulatory space to enable passage of cooling fluid from the space through the first perforations to form a cooling fluid film on the inner surface of the first wall.

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: An arrangement for removably fixing a thermal protection tile on the inside of a combustion chamber wall is described. In one form the tile is provided with a fixing stud which is arranged to pass through a hole in the wall, and a split washer is inserted under the head of the stud to lock the assembly to the wall. In another form the tile is provided with a fixing stud having a head which is arranged to be inserted in a socket welded to the inner surface of the wall and which is locked in place by a stop inserted through a hole in the wall to abut the edge of the head and prevent its removal from the socket.

Abstract: An arrangement for removably fixing a thermal protection tile on the inside of a combustion chamber wall is described. In one form the tile is provided with a fixing stud which is arranged to pass through a hole in the wall, and a split washer is inserted under the head of the stud to lock the assembly to the wall. In another form the tile is provided with a fixing stud having a head which is arranged to be inserted in a socket welded to the inner surface of the wall and which is locked in place by a stop inserted through a hole in the wall to abut the edge of the head and prevent its removal from the socket.

Abstract: A cladded combustion chamber construction is disclosed in which the cladd tiles can be assembled and replaced without the necessity of disassembling the structural wall of the combustion chamber. The combustion chamber has a generally cylindrical wall with external and internal surfaces bounding the combustion chamber and has a plurality of cladding tiles located on one of the external and internal surfaces of the wall. To attach the cladding tiles to the combustion chamber structure, a plurality of channel shaped attaching devices are utilized extending in a generally circumferential direction around the wall of the combustion chamber and having a portion extending generally parallel to the wall, but spaced from the wall. The portion extending parallel to the wall of the combustion chamber has a circumferentially extending cut out portion whose circumferential length is slightly greater than the width of a cladding tile.

Abstract: A fuel injection system for a gas turbine engine combustion chamber is disclosed having a sleeve defining a passageway extending along a longitudinal axis of a combustion zone, a first fuel injector orifice to inject fuel into the passageway, and second fuel injector holes arranged in a plurality of substantially linear arrays extending radially from the sleeve and angularly equidistantly spaced from each other, the second fuel injection holes located in a plane extending substantially perpendicular to the longitudinal axis of the combustion chamber such that the plane is located axially between an upstream end wall of the combustion chamber and the downstream end of the sleeve.

Abstract: A fuel injection system is disclosed which incorporates a plurality of bowl or shroud members extending upstream of an end wall of the combustion chamber between the end wall and an air swirler in which the shroud member has an end joined with the end wall of the combustion chamber having a substantially elongated elliptical cross-sectional configuration. The end wall of the combustion chamber defines an elliptical shaped opening corresponding to the shape of the end of the shroud or bowl member to enable the fuel/air mixture to be atomized as it enters the combustion chamber. The bowl or shroud member may also define a plurality of openings to enable additional air to be mixed with atomized fuel cone.

Abstract: A fuel/oxidizer pre-mixing combustion chamber for a turbojet engine is disclosed in which the pre-mixing device is incorporated into the upstream end wall structure of the combustion chamber. The upstream end portion of the combustion chamber, which is in communication with the oxidizer, has a plurality of generally radially extending, "V"-shaped members oriented such that the vertex of the "V" shape faces in an upstream direction. These members extend generally radially between the inner and outer walls which define the boundaries of the combustion chamber. The members define upstream edges and downstream edges which are axially the upstream edges. Fuel injectors extend radially inwardly between these members and are axially positioned between the locations of the upstream and downstream edges so as to spray fuel onto the adjacent sides of each of the members.

Abstract: A gas separation assembly for a gas turbine engine combustion chamber is disclosed having spaced apart partition walls which extend through an end of the combustion chamber so as to define an oxidizer chamber which communicates with a source of oxidizer. Downstream ends of the spaced apart partition walls within the combustion chamber are interconnected to a plurality of generally "V" shaped spacers oriented such that the apex of the "V" configuration faces toward the end of the combustion chamber. Downstream edges of the partition walls are notched, also in a "V" shaped configuration such that the notches extend between opposite legs of the spacers. The spacers are circumferentially spaced apart so as to define passageways which communicate with the oxidizer chamber to enable oxidizer to pass through the gas separation assembly into the combustion chamber.

Abstract: A system for reducing nitrogen oxide emissions from a gas turbine engine is disclosed in which a portion of air in the air compressor is tapped and supplied to an inlet which introduces at least a portion of the tapped air into the primary zone of the combustion chamber. A control device is disposed between the tap and the inlet to control the air flow passing to the inlet. The inlet is located so as to inject the tapped air into the combustion chamber primary zone at the intersection of adjacent fuel sprays. The control device, which may be an adjustable flap valve or a three-way valve, may also be operatively connected to the throttle control for the gas turbine engine such that the control allows the maximum amount of air to pass into the combustion chamber under full power conditions. The control device is preferably mounted outside the engine casing enclosing the combustion chamber to allow easy access for assembly and maintenance.