Abstract: A method and apparatus for detecting a fouled fluid filter are disclosed in which the fluid pressure at the outlet of the fluid filter is corrected by a correction pressure to determine a corrected pressure drop. Such a corrected pressure drop has a mathematical function which passes through a maximum magnitude before the fluid flowing through the fluid filter reaches a maximum value. The corrected pressure drop is monitored during the operation of the fluid filter and when the corrected pressure drop reaches a predetermined threshold value, before the engine with which the fluid filter is associated reaches its maximum power, an alarm will be actuated.

Abstract: An anti-icing system to prevent the formation of ice on, or to remove ice from selected portions of a gas turbine engine is disclosed that is not directly dependent upon the mode or speed of operation of the gas turbine engine. The system has a heat exchanger into which flows a tapped portion of air from the compressor and fuel from the engines fuel supply system. The fuel supply system includes a fuel return circuit which connects the fuel pump outlet to the fuel pump inlet so as to return or recycle fuel to the fuel pump inlet when the engine demand for fuel is low, such as under lower power operating conditions. This recycling of the fuel raises the temperature of the fuel such that, in the heat exchanger, heat is transferred to the tapped portion of the air from the compressor thereby raising the temperature of such tapped air such that it may be directed onto selected portions of the gas turbine engine to either prevent formation of ice, or to remove ice from these portions.

Abstract: A gas turbine engine is disclosed having an air compressor and a generally annular combustion chamber, with a generally annular diffuser located between the compressor and the combustion chamber so as to direct air exiting from the compressor toward the combustion chamber. The diffuser has inner and outer walls and defines an exit which is located adjacent to an opening in an upstream wall portion of the combustion forming a dome cowl. The dome cowl divides the air emanating from the diffuser exit into a primary air stream passing through the opening and one or more secondary air streams which pass between the walls defining the combustion chamber and the walls of a casing enclosing the combustion chamber assembly. A guide is associated with the diffuser for directing water in the air passing through the diffuser away from the opening such that it will not pass directly into the combustion chamber.

Abstract: A system is disclosed for detecting a malfunction in a fuel/lubricating oil heat exchanger which includes a pressure differential generator located in the pressure balancing conduit connecting the lubricating oil reservoir with the lubricating enclosure. The pressure differential generator may be a cavitation venturi tube having a throat which, under normal conditions, allows sub-sonic fluid flow which enables the air in the lubricating enclosure to freely communicate with the interior of the oil reservoir and vice versa. When fuel is mixed with the lubricating oil, due to a malfunction in the fuel/oil heat exchanger, the fuel enters the lubricating oil reservoir causing the fluid level within the reservoir to rise and overflow. The cavitation venturi tube is then supplied with a comparatively hot mixture of fuel and oil having a vapor pressure approximately equal to the reference pressure within the lubricating enclosure.

Abstract: An anti-flameout safety system for a gas turbine engine is disclosed which prevents engine flameout in the event of ingestion of hail and/or water through the engine intake. The anti-flameout safety system has a detector to detect the water concentration in the engine which generates a signal when the water concentration is at or above a predetermined level and an engine control means which is associated with the detector such that, when the detector generates the signal, the engine control means automatically increases the engine power output.

Abstract: A sealed transmission assembly coupling a first rotary shaft mounted in a first casing to a second rotary shaft substantially aligned with the first shaft and mounted in a second casing fixed to the first casing is disclosed which enables replacement of leaky seals or part of the transmission chain to be effected quickly and without disconnecting the second casing from the first casing.

Abstract: In order to limit the heating of fuel in the fuel supply circuit of an aircraft turbo-engine including a high pressure displacement pump driven by the turbo-engine, and an excess fuel return pipe having a pressure regulating valve in parallel with the high pressure pump, a driving unit, such as a turbine, is disposed in the return pipe downstream of the regulating valve to be driven by excess fuel flowing in the pipe. The driving unit may be drivingly connected directly to the drive shaft of the high pressure pump, or indirectly through a gear box through which the turbo-engine is also connected to the drive shaft.

Abstract: In a turbojet aero-engine of the bypass type in which the compressor includes pivotally mounted blow-off valves for discharging air from the primary air flow path through the compressor to prevent surging, the compressor further includes pivoted means associated with the blow-off valves such that the pivoted means lie against the wall of the primary air flow path whenever the valves are closed or are open below a predetermined angle of opening and, when said valves are opened beyond said predetermined angle, the pivoted means are caused to project into the primary air flow path for collecting excess water carried by the air and discharging this water from the flow path.

Abstract: The spindle of a butterfly valve for controlling the supply of compressed air to the starter of a turbine aero-engine is rotated to open and close the valve by the linear movement of a slide in a cylinder in response to the pressure differential between a pair of chambers defined by the slide and the cylinder. A resilient mechanism is provided for holding the slide when the valve is closed and temporarily preventing movement of the slide to open the valve until a predetermined minimum pressure difference exists between the two chambers. The slide is then released and travels initially at high speed and then at a speed limited by a throttle venting the lower pressure chamber to atmosphere. This makes it possible to create a relatively high rate of increase in the pressure of air supplied to the starter at the commencement of opening of the butterfly valve while controlling the final rate of pressure rise. The device can thus be used equally with an inertia starter or a free wheel starter.

Abstract: In a turbine plant having a starter housed in a starter chamber containing splash lubrication oil bath, the plant lubrication circuit is arranged to feed clean oil to a non-polluting chamber disposed intermediate the starter chamber and the chamber of the power take-off unit of the plant. The partition separating the starter chamber and the intermediate chamber has at least one through passage so that the oil baths of the two chambers are in permanent communication, and the passage is fitted with a filtering strainer to prevent contaminants entering the intermediate chamber, and hence the plant lubrication circuit, from the starter chamber. The partition between the intermediate chamber and the chamber of the power take-off unit is provided with an overflow passage so that excess oil in the intermediate chamber flows freely into the power take-off chamber.

Abstract: A device and method are disclosed to reduce the self-heating of the fuel in an aircraft turbojet engine fuel system by inducing cavitation in a positive displacement pump in the system. The cavitation is induced by modulating the charging or inlet pressure of the pump by the action of a modulating or regulating valve placed in the pump inlet line.

Abstract: An hydraulic jack having more than two chambers is disclosed and is intended for use in a system of jacks, the displacement of which is to be synchronized. Each jack has a cylindrical center cavity in which a piston with a cylindrical cross section reciprocates, an annular cavity in which a piston with an annular cross-section reciprocates, and a rod for transmitting thrust connected to both pistons. In order to provide the jack with a minimum longitudinal dimension and with maximum rigidity, the two cavities are concentric and are separated by a stationary intermediate wall. The two pistons are connected to the rod for the transmission of thrust.

Abstract: A device and method are disclosed for monitoring the cavitation parameters of a positive displacement fuel pump. A flow proportional to the flow of the pump is branched off a supply line to a cavitation venturi at a pressure lower than the supply pressure, while regulating the proportional flow and the venturi so that the latter attains its cavitation range prior to the cavitation of the positive displacement pump. In this range, the pressure at the inlet of the venturi is equal to the critical feeder pressure of the volumetric pump. The difference between the supply pressure of the positive displacement pump and the pressure of the inlet of the venturi is detected and a control signal generated to activate an alarm or increase the pressure of the supply fluid.

Abstract: System for measuring the temperature of a gas by sampling, having a measurement probe with a certain permanent error. The system includes in addition two corrective probes placed in contact with said gas sample, one of the probes having essentially the same error as the measurement probe, the other probe having a double error. These three probes are advantageously thermocouples connected in opposition in a predetermined order so that the measurement error .DELTA.T obtained by the measurement probe in relation to the real temperature of the gases Tg is compensated for by those from the corrective probes.