Pratt-whitney Canada Corp

Pratt & Whitney Canada Corp.

Kashif Mohammed

John Sgouromitis

Sylvain Lamarre

Patrick Manoukian

Benjamin James Renaud

Patrice Remy

Robin Watt

Vivek Bhat

Benjamin Renaud

An aircraft engine has an exhaust duct receiving an engine gas flow and a heat exchanger duct having a wall extending from an inlet receiving a cooling air flow to an outlet connected to the exhaust duct. A heat exchanger is disposed in the heat exchanger duct between the inlet and outlet. A diverted airflow pathway in the heat exchanger duct includes first and second plates extending inwardly in the heat exchanger duct from first and second positions on an inner surface of the wall to plate distal ends, the plate distal ends extending past one another in a direction transverse to the wall. A valve in the wall selectively fluidly connects the heat exchanger duct to an evacuation location and is movable between closed and open positions during operating and shutdown conditions of the engine to fluidly disconnect and connect the heat exchanger duct to the evacuation location.

Engine exhaust reverse flow prevention

An assembly for an aircraft includes an aircraft housing, an auxiliary power unit (APU), an oil system, a door actuator, and a controller. The aircraft housing forms a compartment. The aircraft housing includes an intake door. The intake door is movable between a closed position, an open position, and intermediate positions between the closed position and the open position. The APU is disposed within the compartment. The APU includes an engine. The engine includes an air inlet and a rotational assembly. The oil pump is operatively connected to the rotational assembly. The door actuator is operatively connected to the intake door. The door actuator is operable to position the intake door in the closed position, the open position, and the intermediate positions to control an ambient air flow to the air inlet. The controller is operatively connected to the door actuator. The controller is configured to identify a fire condition within the compartment, identify a fire position of the intake door, and control the door actuator to position the intake door in the fire position. The fire position is one of the open position or the intermediate positions.

Aircraft engine assembly for controlling engine oil flow during fire conditions and method for using same

A gas turbine engine includes a compressor section and a turbine section. A heat exchanger is operable to cool a fluid utilized by a component of the gas turbine engine. The heat exchanger has an inlet and an outlet for the accessory fluid. A strain gauge is associated with the fluid inlet and operable to produce a signal indicative of a temperature of the fluid at the fluid inlet and a strain gauge is associated with the fluid outlet and operable to produce a signal indicative of a temperature of the fluid at the fluid outlet. A controller determines a temperature differential across the heat exchanger by utilizing the signal from the strain gauge at the fluid inlet and the signal from the strain gauge at the fluid outlet. A method and a heat exchanger are also disclosed.

Heat exchanger differential oil temperature determination

An aircraft engine reservoir system includes a reservoir inner chamber containing a flammable fluid. A chamber inlet is fluidly connectable to a flammable fluid source pressurizing the fluid. The chamber includes an outlet. An air source operates at a pressure that is lower that a flammable fluid pressure during an engine operational condition. A valve selectively fluidly connecting the chamber to the air source is movable between a closed position, in which the chamber flammable fluid pressure acting on the valve exceeds the air source pressure acting on the valve such that the valve blocks the air from entering the chamber, and an open position, in which the chamber flammable fluid pressure acting on the valve is lower than the air source pressure acting on the valve such that the valve allows the air to flow into the chamber and evacuate the flammable fluid from the chamber through the outlet.

Flammable fluid reservoir

An aircraft engine, has: a fluid system including a component adapted for containing a volume of the fluid, the fluid circuit further including a bypass conduit bypassing the component, and a valve fluidly connected to the fluid circuit upstream of the component relative to a flow of the fluid towards the component, the valve having an open configuration fluidly connecting the source of the fluid to the bypass conduit through the valve and a closed configuration in which the valve connects the source of the fluid to the component, the valve movable from the open configuration to the closed configuration in response to the fluid being at a first temperature, and the valve movable from the closed configuration to the open configuration in response to the fluid exerting an opening force on the valve and the fluid being at a second temperature different than the first temperature.

Aircraft engine fluid system with bypass valve

An aircraft engine comprises an exhaust duct receiving an engine gas flow at a first pressure during an operating condition and at a second, lower pressure at shutdown. A heat exchanger duct connected to the exhaust duct has a heat exchanger disposed therein. A cover in the heat exchanger duct includes a closure movable between open and closed positions to fluidly connect or disconnect the heat exchanger duct to the exhaust duct. A biasing member disposed in the exhaust duct, exposed to the gas flow, and operatively connected to the closure biases the closure toward the closed position with a biasing force. First and second forces opposing the biasing force are generated on the biasing member by the gas flow at the first and second pressures, the first being greater than the second. The biasing force is greater than the second force and less than the first force.

An aircraft engine, has: an oil system, a component containing a baseline volume of oil during normal operation greater than a maximum volume of the oil for compliance with fire resistance requirements, the oil system having: an oil circuit, a de-priming port fluidly connected to a fluid source at a pressure sufficient to overcome a pressure drop through the component to drain the component to a volume of oil less than the maximum volume of the oil for compliance with the fire resistance requirements, and a valve connected to the de-priming port, the valve having a closed configuration preventing the fluid from entering the oil circuit and an open configuration permitting the fluid to enter the oil circuit via the de-priming port and through the valve, the valve movable from the closed configuration to the open configuration in response to the component being subjected to a fire event.

Method and system for de-priming an aircraft engine component containing a flammable fluid for fire safety

A fire protection device for an accessory of an aircraft engine includes a baffle located within an airflow passage in communication with the accessory, the baffle having fire shield elements made of a shape memory alloy. The fire shield elements are deformable between a deformed state and a natural state, wherein in the natural state the fire shield elements extend at least partially across the airflow passage to protect the accessory from flames, and in the deformed state the fire shield elements is bent to define one or more gaps between the fire shield elements in the air flow passage thereby allowing airflow through the baffle.

Engine accessory fire shield

An aircraft engine, has: a fluid system including a fluid circuit fluidly connecting a plurality of components to a source of a fluid, the fluid being flammable, a component of the plurality of components containing a volume of the fluid during normal operation; and a valve fluidly connected to the fluid circuit upstream of the component relative to a flow of the fluid towards the component, the valve having an open configuration fluidly connecting the source of the fluid to the component through the valve and a closed configuration in which the valve disconnects the source of the fluid from the component, the valve movable from the open configuration to the closed configuration in response to the component being subjected to a fire event.

Aircraft engine fluid system with shut-off valve

A cover system selectively allows a gas flow through a heat exchanger duct upstream of an exhaust duct in an aircraft engine. A fluid is at a first pressure during an engine operating condition and a second pressure lower than the first during shutdown. A plate extends across the heat exchanger duct with aperture(s) extending therethrough. A closure is movable between an open position with gas flowing through the apertures into the exhaust duct, and a closed position with the closure closing the apertures. A biasing member operatively connected to the closure closes the closure with a biasing force. During the engine operating condition, the first pressure creates a first force acting against and greater than the biasing force to urge the closure open. At shutdown, the second pressure creates a second force acting against and lower than the biasing force, the biasing force biasing the closure closed.

A heat exchanger, has: a heat exchanger core having an inlet, an outlet, at least one first conduit connecting the inlet to the outlet, and at least one second conduit in heat exchange relationship with the at least one first conduit; a bypass conduit connecting the inlet to the outlet while bypassing the at least one first conduit; and a valve in communication with the bypass conduit and having: a valve member movable between a closed position in which fluid communication through the valve and via the bypass conduit is blocked and an open position in which fluid communication through the bypass conduit and through the valve is permitted, the valve member defining an auxiliary passage, and a thermal fuse overlapping the auxiliary passage and blocking fluid communication through the valve member via the auxiliary passage, the thermal fuse having a melting temperature above a predetermined temperature of the fluid.

Heat exchanger with bypass valve and thermal fuse

A gas turbine engine according to a first embodiment, having a case; a core within the case; an exhaust nozzle that is fluidly coupled to the case; a duct having a duct outlet that is fluidly coupled to the exhaust nozzle and a duct body extending from the duct outlet to a duct inlet; an air/oil cooler having an airflow outlet disposed at the duct inlet and a cooler body extending from the airflow outlet to an airflow inlet; and an airflow control baffle disposed at one of: the duct inlet; the duct outlet; and the airflow inlet of the cooler, wherein the airflow control baffle is configured to open when oil temperature in the engine is above a first threshold and close when the oil temperature is below a second threshold that is lower than the first threshold.

Gas turbine engine with air/oil cooler having an airflow control baffle

An aircraft engine includes a core gas path through which a core gas flow flows, an exhaust duct receiving the core gas flow, an air-cooled heat exchanger disposed in a heat exchanger duct having an air inlet providing cooling air to the air-cooled heat exchanger and an air outlet in fluid communication with the exhaust duct, and a cover disposed in the heat exchanger duct downstream of the air-cooled heat exchanger. The cover is movable between an open position, in which the cover allows the cooling air to flow through the air outlet into the exhaust duct, and a closed position, in which the cover substantially blocks the air outlet. The cover is operable to move from the open position to the closed position at a predetermined temperature of the cover.

Methods and systems for controlling windmilling in an engine are described. An electric starter motor is coupled to the engine, a circuit element is coupled to the electric starter engine and to a DC signal source, and a control system coupled to the engine and to the circuit element. The control system is configured for: determining whether the engine is in a windmilling state; when the engine is in a windmilling state, commanding the circuit element to apply a DC signal to the electric starter motor; and modulating the DC signal applied to the electric starter motor to control a level of rotational motion of the engine.

Growing community of inventors

Brossard, Canada

Kashif Mohammed