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 separator-diffuser for a gas turbine engine is disclosed wherein the diffuser includes axial walls which function as a guide vane stage for the oxidizer compressor. By incorporating the last, or downstream, guide vane stage into the diffuser structure, the overall axial length and bulk of the gas turbine engine may be significantly reduced. The separator-diffuser has a wall defining a generally annular oxidizer flow passage extending around the central axis of the gas turbine engine, the passage having an oxidizer inlet located downstream of the last rotor stage of the oxidizer compressor so as to enable the oxidizer to pass from the oxidizer compressor into the oxidizer flow passage. A generally annular separator member is located in the oxidizer flow passage downstream of the oxidizer inlet so as to divide the oxidizer flow passage into at least two separate oxidizer flow paths, each flow path having a separate oxidizer outlet.

Abstract: A diffuser for a turbojet engine is disclosed in which a plurality of diffuser inlets are arranged in a substantially circular array bounded by inner and outer diffuser walls and by a plurality of partitions extending generally radially from the axis of the annular diffuser. The plurality of diffuser inlets are located so as to receive air or oxidizer from the turbojet engine compressor and the radial partitions may be integrated into the compressor guide vanes. The diffuser has a plurality of sets of diffuser outlets, each set comprising a plurality of diffuser outlets arranged in a circular array about the central axis of the diffuser. The radius of each set of diffuser outlets is different from the radius of each of the other sets of diffuser outlets such that the entirety of diffuser outlets comprise a non-circular array.

Abstract: A wall structure for a gas turbine engine structure, such as a combustion chamber or an afterburner duct is disclosed having a plurality of cooling orifices formed through the wall located in a plurality of odd and even transverse rows, each row having a plurality of cooling orifices located in a plane extending substantially perpendicular to a longitudinal axis of symmetry with the cooling orifices of each odd and even row being circumferentially offset from the cooling orifices of the adjacent upstream corresponding odd and even row. The cooling orifices have a common diameter D and are circumferentially offset a distance d such that distance d is between 0.5 D and D. The axes of the orifices in the odd numbered rows lie on a first main line extending obliquely to the longitudinal axis of symmetry and to the oxidizer air flow, and the axes of orifices on the even numbered rows lie on a second main line, also extending obliquely to the longitudinal axis of symmetry and to the oxidizer air flow.

Abstract: The present invention relates to a method and apparatus for supplying fuel to and cooling a fuel injector of a gas turbine engine having a dual head combustion chamber. The method comprises the steps of supplying a total fuel flow to the fuel injector such that at least a portion of the total fuel flow circulates through the high power injector nozzle during all operational modes of the gas turbine engine, including those modes in which the high power injector is not supplying fuel to the combustion chamber, and evacuating unused fuel from the high power injector.

Abstract: A gas flow separator for an annular combustion chamber of a gas turbine engine is disclosed in which the radially spaced apart first and second gas flow separator walls which extend axially into the combustion chamber from the combustion chamber upstream end wall each define a plurality of axially extending channels. Each of the channels extends generally axially in an upstream direction from the downstream edge of each of the separator walls such that their axial lengths are less than the axial lengths of the respective separator walls. Both the depth and the width of each of the channels increases from its upstream end point to the downstream edges of the separator walls. The channels may be circumferentially aligned with each other, or the channels of one separator wall may be circumferentially offset from the channels of the other separator wall.

Abstract: A combustion chamber for a gas-turbine engine is disclosed in which the walls defining the combustion chamber may be easily attached to and removed from the engine structure. A dome member is attached to the engine structure such that it partially encloses the fuel injector nozzle in an upstream direction. The shape of the dome-member is such that it splits the incoming oxidizer flow into inner and outer flows which pass along the inner and outer sides of the combustion chamber. The inner and outer walls of the combustion chamber may be attached to an upstream end wall of the combustion chamber such that this assembly is removable as a unit from the dome member. The inner and outer walls, as well as the end wall, are releasably attached to the dome member such that the assembly can be removed from the gas-turbine engine without the necessity of removing or displacing the fuel injector nozzles or the dome member.

Abstract: A separator for an annular gas turbine engine combustion chamber is disclosed having a plurality of separator segments arranged in a generally annular configuration to form an annular separator extending from an upstream end wall of a combustion chamber into the combustion chamber so as to separate first and second combustion zones within the combustion chamber. Each of the separator segments has a hollow interior defined by a front wall, an outer wall, an inner wall which has at least a portion tapering or converging towards the outer wall in a direction extending away from the front wall, and first and second sides. The sides define an array of holes communicating with the hollow interior, the positioning of the array of holes on a first sides being different from that of the array of holes on the second sides such that the axes of the holes are out of alignment with each other.

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 turbine engine combustion chamber is disclosed having multiple sets of fuel injectors. A set of first fuel injectors are arranged in two radially inner and outer generally circular first arrays such that the fuel injectors of one array are located circumferentially between the fuel injectors of the other array. The combustion chamber also includes a set of second fuel injectors which are also arranged in two generally circular, radially inner and outer arrays such that, in each array, the second fuel injectors are located circumferentially between the first fuel injectors. In a circumferential direction, the positions of the first and second fuel injectors vary between the radially outward array and the radially inward array. One set of fuel injectors may operate under idle and low power operating conditions, while the other set of fuel injectors inject fuel into the combustion chamber during full power take off or cruise operations.

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.

Abstract: A fuel system for a turbojet engine is disclosed in which the operating parameters of the engine are improved throughout the range of engine operating conditions. The fuel system includes an enlarged intermediate bowl for the combustion chamber which increases the reactive volume, while at the same time provides sufficient cooling of the bowl to avoid burn-through or uneven engine operating characteristics. The bowl extends radially outwardly beyond an opening in the base of the combustion chamber and defines a row of air inlet orifices which serves to more completely atomize the fuel prior to its ignition. A diaphragm control system may also be utilized to control the amount of air flowing into the bowl as the engine speed changes.

Abstract: The control device comprises at least one control ring to which one end of n elbow lever is articulated. The vane pivot of alternating vanes is fixed at the intersection of the arms of the elbow levers. The other end of each elbow lever is connected by a rod to the end of a straight lever, the other end of which is fixed to the pivot of an adjacent vane. The circumferential movement of the ring causes the pivots of the adjacent vanes to pivot in opposite directions. Two other embodiments have two rings.