A gas turbine engine includes a compressor section, a combustor, and a turbine section. A bleed tap taps air from the compressor section through a bleed valve. The bleed valve is selectively opened by a control to dump air from the compressor section to a dump outlet. A heat exchanger duct includes a duct air inlet to cool a fluid in a heat exchanger and a duct air outlet. The dump outlet is within the heat exchanger duct.

A gas turbine engine includes a compressor section, a combustor, and a turbine section. A bleed tap taps air from the compressor section through a bleed valve. The bleed valve is selectively opened by a control to dump air from the compressor section to a dump outlet. A heat exchanger duct includes a duct air inlet to cool a fluid in a heat exchanger and a duct air outlet. The dump outlet is within the heat exchanger duct.

A turbofan gas turbine engine includes, in axial flow sequence, a heat exchanger module, a fan assembly, a compressor module, and a turbine module. The fan assembly includes fan blades defining a corresponding fan area (A.sub.FAN). The heat exchanger module is in fluid communication with the fan assembly by an inlet duct, and includes radially-extending vanes arranged in a circumferential array with at least one vane including a heat transfer element for heat transfer from a first fluid contained within each element to an airflow passing over a surface of each heat transfer element before entering the fan assembly inlet. Each heat transfer element extends axially along the corresponding vane, with a swept heat transfer element area (A.sub.HTE) being the wetted surface area of all heat transfer elements in contact with the airflow. A Fan to Element Area parameter F.sub.EA of A.sub.HTE/A.sub.FAN lies in the range of 47 to 132.

A method for energy conversion for a vehicle is provided. The method including extracting a flow of compressed fluid from a compressor section of a propulsion system; flowing the flow of compressed fluid to a turbine operably coupled to a driveshaft, in which the driveshaft is operably coupled to a load device; expanding the flow of compressed fluid through the turbine to generate an output torque at the driveshaft to operate the load device; and flowing the expanded flow of compressed fluid from the turbine to thermal communication with a thermal load.

A propulsion unit for an aircraft includes a nacelle, a turbojet engine, an annular flow path for circulating a secondary air flow, and a precooler device communicating with a motor enclosure and including a scoop opening into the annular flow path. The propulsion unit includes a compressed air supply circuit arranged in the propulsion unit for injecting a flow of compressed air into the scoop of the precooler device. A method for ventilating a motor enclosure of a propulsion unit includes injecting compressed air into a scoop of the precooler device when the turbojet engine is stopped.

A propulsion unit for an aircraft includes a nacelle, a turbojet engine, an annular flow path for circulating a secondary air flow, and a precooler device communicating with a motor enclosure and including a scoop opening into the annular flow path. The propulsion unit includes a compressed air supply circuit arranged in the propulsion unit for injecting a flow of compressed air into the scoop of the precooler device. A method for ventilating a motor enclosure of a propulsion unit includes injecting compressed air into a scoop of the precooler device when the turbojet engine is stopped.

A front centre body (FCB) structure for a geared turbofan engine comprises a plurality of vanes extending across the inlet duct to a low pressure compressor and integrates a heat exchanging arrangement to control the temperature of the gearbox of the turbofan engine.

A heat exchanger between a fluid and an air flow, includes a heat exchange wall separating the fluid and the air flow, the heat exchange wall including a heat exchange surface that extends parallel to a longitudinal direction of the air flow and with which the air flow is in contact. The heat exchange wall includes at least one turbulence generator extending in a hollow manner in relation to the heat exchange surface.

An apparatus and method of forming a hybrid heat exchanger including a first manifold defining a first fluid inlet and a second manifold defining a second fluid inlet. A monolithic core body includes a first set of flow passages in fluid communication with the first manifold and a second set of flow passages is in communication with the second manifold. At least a portion of the first manifold or the second manifold has a tunable coefficient of thermal expansion that is less than a coefficient of thermal expansion of the structurally rigid monolithic core.

An apparatus and method of forming a hybrid heat exchanger including a first manifold defining a first fluid inlet and a second manifold defining a second fluid inlet. A monolithic core body includes a first set of flow passages in fluid communication with the first manifold and a second set of flow passages is in communication with the second manifold. At least a portion of the first manifold or the second manifold has a tunable coefficient of thermal expansion that is less than a coefficient of thermal expansion of the structurally rigid monolithic core.