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 system is disclosed for regulating oil and fuel temperatures in a turbojet engine having an engine accessory driven at constant speed by a power transmission which is driven by the turbojet engine. The system has a first closed oil circuit for circulating oil through the turbojet engine, a second closed oil circuit for circulating oil through the power transmission, a fuel circuit for supplying fuel to the turbojet engine, an air/oil heat exchanger connected to the first closed oil circuit to pass oil in heat exchange relationship with air, an oil/fuel heat exchanger connected to the fuel circuit and to the first closed oil circuit downstream of the air/oil heat exchanger to pass oil and fuel in heat exchange relationship, and an oil/oil heat exchanger connected to the first and second closed oil circuits to pass oil in heat exchange relationship, the connection to the first closed oil circuit being downstream of the oil/fuel heat exchanger.

Abstract: An actuating system for a variable area exhaust nozzle is disclosed having inner and outer flaps pivotally connected to an airframe whose positions may be varied by a single set of control cylinders. The control cylinders have a case in which is slidably mounted a pair of pistons, each having piston rods extending from one side, which piston rods extend through one end of the cylinder case. The piston rods may be arranged coaxially to minimize the bulk of the actuating cylinder. One of the piston rods is connected to the inner flaps, while the other of the piston rods is connected to the outer flaps.

Abstract: A seal for sealing the gaps between adjacent turbine blade structures is disclosed in which the seal is disposed in a compartment formed between adjacent turbine blade structures having first and second sealing surfaces adjacent to a generally axially extending gap and a generally radially extending gap, respectively. The seal also has a thrust surface extending obliquely to a radius from the axis of rotation of the rotor disk to which the turbine blade structures are attached which is engaged with a reaction surface formed on a reaction member located in the compartment. During rotation of the rotor disk, centrifugal force acting in a radially outward direction is transmitted both radially and axially to a seal by contact between the reaction surface and the oblique thrust surface to cause the first sealing surface to seal the generally axially extending gap and the second sealing surface to seal the generally radially extending gap.

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: The present invention relates to an apparatus for detecting operational anomalies in a pressurized fluid circuit having a main pump, a fluid filter and a booster pump connected in series. The apparatus has an indicating detector to provide an indication of a system malfunction and a switching device connected to the indicating detector, as well as to various points in the pressurized fluid circuit, to enable the indicating detector to detect a malfunction in either the booster pump or the filter. The switching device has pressurized fluid inlets connected to a point upstream of the booster pump, a point between the booster pump and the filter inlet and to a point between the filter outlet and the inlet of the main, high pressure pump.

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 improved turbine vane structure is disclosed which enables more effective cooling and the reduction of temperature gradients along its length. The hollow interior of the vane is divided into three separate cavities, two upstream cavities and a downstream cavity. The downstream cavity is partially filled with a body of porous, heat transfer material. Cooling air flows through the downstream cavity in a direction counter to the hot gases passing over the exterior surface of the vane so as to increase the heat exchange properties. The two upstream cavities lie adjacent to each other and are supplied with cooling air from opposite directions to achieve a counterflow, heat exchange effect. Several sets of cooling holes are provided through the vane wall to communicate with the interior cavities and supply cooling air to the exterior surface of the vane.

Abstract: The present invention relates to a system for cooling a high power fuel injector of a dual fuel injector wherein the system comprises a first fuel supply circuit having a first conduit connecting a fuel feed supply and the high power fuel injector, the first conduit having a terminal end adjacent to a distal end of the high power fuel injector, and a second conduit connecting the terminal end of the first conduit to the low power fuel injector such that all of the fuel supplied to the low power injector first passes through the high power fuel injector. The system also has a second fuel supply circuit, separate from the first fuel supply circuit, which comprises a third conduit connecting the fuel feed supply and the fuel injection orifices of the high power fuel injector so as to supply fuel to the fuel injection orifices.

Abstract: An apparatus for detecting fuel vapors in a turbojet engine oil tank is disclosed which incorporates a device in the oil tank which senses the presence of fuel vapors in the oil tank. The device has a housing defining an inner chamber in which a piston is slidably located. An actuating cartridge is also located in the chamber between an end wall of the housing and the piston. The cartridge comprises a material which expands in volume when subjected to heat and one which produces an exothermic reaction in the presence of fuel vapors. The housing defines one or more orifices to enable the atmosphere within the tank to communicate with the actuating cartridge.

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 stator vane mounting platform is disclosed which provides internal cooling chambers which facilitates the flow of cooling air through the chambers and thus, the cooling of the stator assembly. Baffles define an upstream chamber and a downstream cooling chamber between adjacent stator vanes so as to maximize the airflow and, consequently, the cooling effects of this airflow. The internal cooling chambers are defined by a thick wall and a relatively thin wall, the thin wall being in direct contact with the hot gases passing through the stator assembly. Mounting lugs and flanges are directly attached to the thicker wall so as to mount the stator assembly to the turbine engine structure and to accommodate all of the mechanical stresses encountered during the turbine engine operation.

Abstract: A turbojet engine has an outlet duct to which an annular array of actuating cylinders for nozzle flaps are hinged. The housings for the cylinders are connected together by transverse members to form a rigid structure coaxial with the outlet duct. The arrangement includes convergent flaps and slaving devices for divergent flaps, all hinged to the rigid structure and particularly to the housings.

Abstract: A self regulating bleed valve for a gas turbine engine is provided which taps or bleeds a portion of a gas, typically air, from a duct of the gas turbine having a wall bounding the gas flow. The bleed valve has a valve member pivotally attached to the wall such that the valve member extends through a main opening formed in the wall. The valve member has an internal cavity in communication with a gas inlet opening and a gas exhaust opening and is pivotally movable between an extended position wherein the gas inlet opening portion of the valve member extends into the gas flow duct such that the inlet opening faces generally in an upstream direction so as to deflect a portion of gas flow into the internal cavity, and a retracted position wherein the inlet opening extends obliquely, generally parallel, to the gas flow so as to minimize the air tapped or bled from the gas flow.

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 fuel supply system for a gas turbine engine is disclosed which incorporates a discharge conduit into the fuel supply system such that an increase in the temperature of the fuel in the fuel injector conduits after engine shut-down will cause a valve in the discharge line to open before the opening of the valve in the fuel injector conduit, thereby directing excess fuel to a receiver or a tank, rather than into the hot combustion chamber. A fuel flow valve is connected to the fuel supply conduit, the discharge conduit, as well as the fuel injector conduits. Under normal operating conditions, a valve member within the fuel flow valve is positioned so as to enable communication between the fuel feed conduit and the fuel injector conduits so that fuel may be supplied to the fuel injectors. When the valve element is moved the a second position, after engine shut-down, it seals off the fuel feed conduit and enables communication between the fuel injector conduits and the discharge conduit.

Abstract: A rotary valve assembly is disclosed in which a rotary valve member is located within a casing having one or more fluid inlets and a plurality of fluid outlets. The rotary valve member has a fluid conduit which extends in a generally radial direction and which communicates with the fluid inlet. Fluid orifices communicate with the fluid conduit and exit through opposite sides of the rotary valve member to thereby minimize, or eliminate altogether, axial forces acting on the rotary valve member. Fluid outlet passages communicate with the two fluid orifices during at least pan of the rotation of the rotary valve member to direct the pressurized fluid to the valve outlets. The rotary valve may include a pair of rotary valve members drivingly connected to each other such that they rotate synchronously. The connection may include gear teeth formed on the adjacent peripheries of the rotary valve members such that rotation of one of the valve members causes rotation of the other.

Abstract: A control device makes it possible to rapidly shift the bleed valves of an aircraft turbojet engine to a large opening position when the engine is under low power operation in order to prevent flame-out. The device allows for instantaneously interrupting the action of a control return cable when the valves are open from a certain given value. The device includes a drive support integral with a crank handle, in order to bring about the translation of the return cable, when the latter is not blocked by a translation stop member. The control device is used for opening of bleed valves of turbojet engines having two concentric annular jets.

Abstract: A method and apparatus for detecting internal defects in a workpiece are disclosed which uses time inversion to invert echo signals received by a transducer from the workpiece with respect to the signal shape and its time distribution and retransmits the inverted signal onto the workpiece. The method involves transmitting an unfocused ultrasonic beam onto the workpiece, receiving an echo signal from the workpiece, storing the first echo signal and inverting the first echo signal from each transducer with respect to the signal shape and time sequence. The inverted signal is transferred to a memory and the aforementioned procedure is carried out for each of the inspection zones n on the workpiece. The stored, inverted first echo signals are then transmitted onto the workpiece, each inverted signal being transmitted onto the inspection zone n from which the non-inverted first echo signal was received.

Abstract: A pressurized fluid flow regulator for controlling fluid in a fluid circuit is disclosed having a high pressure feed chamber in fluid communication with a source of pressurized fluid and with an exhaust chamber which, in turn, has a fluid outlet connected to the device to receive the pressurized fluid. A first valve controls the flow of fluid between the high pressure feed chamber and the exhaust chamber, while a second valve opens and closes the fluid outlet of the exhaust chamber. The regulator also includes a bypass chamber having an inlet in fluid communication with the high pressure feed chamber and an outlet in communication with the inlet of the source of pressurized fluid. A valve system controls the opening and closing of the bypass chamber inlet such that the inlet is opened when the fluid pressure in the high pressure feed chamber exceeds a threshold value so as to avoid over pressurization of the fluid in the system.