A cooling system for a gas turbine engine may comprise a plenum extending circumferentially around an outer engine case structure. The plenum may comprise a supply conduit and a return conduit. The supply conduit and the return conduit may be in fluid communication with a heat exchanger. The heat exchanger may be disposed between the outer engine case structure and an inner engine case structure. The plenum may be configured to provide enhance heat transfer for the cooling system.

An engine assembly includes an engine compartment containing an internal combustion engine and a cooler compartment adjacent the engine compartment containing a heat exchanger. The engine and cooler compartments have an opening defined therebetween. A forced air system is operable to drive an airflow. A method for cooling the engine and its compartment is disclosed.

There is disclosed a cooling system for a liquid cooled internal combustion power plant housed in an engine compartment in a tail cone of an aircraft. The cooling system has: a tail cone inlet defined through a wall of the tail cone and fluidly communicating with an environment; a wall inlet defined through a firewall of the engine compartment; a blower within the engine compartment and having a blower inlet and a blower outlet, the blower inlet fluidly communicating with the environment via the tail cone inlet, via the wall inlet, and via an interior of the engine compartment; a blower outlet defined through a wall of the aircraft and fluidly communicating with the environment; and a cooling flow path extending from the tail cone inlet to the air outlet and across the wall inlet, the cooling flow path in heat exchange relationship with the power plant.

A cooling system for a gas turbine engine may comprise a plenum extending circumferentially around an outer engine case structure. The plenum may comprise a supply conduit and a return conduit. The supply conduit and the return conduit may be in fluid communication with a heat exchanger. The heat exchanger may be disposed between the outer engine case structure and an inner engine case structure. The plenum may be configured to provide enhance heat transfer for the cooling system.

There is disclosed a cooling system for a liquid cooled internal combustion power plant housed in an engine compartment in a tail cone of an aircraft. The cooling system has: a tail cone inlet defined through a wall of the tail cone and fluidly communicating with an environment; a wall inlet defined through a firewall of the engine compartment; a blower within the engine compartment and having a blower inlet and a blower outlet, the blower inlet fluidly communicating with the environment via the tail cone inlet, via the wall inlet, and via an interior of the engine compartment; a blower outlet defined through a wall of the aircraft and fluidly communicating with the environment; and a cooling flow path extending from the tail cone inlet to the air outlet and across the wall inlet, the cooling flow path in heat exchange relationship with the power plant.

An engine assembly includes an engine compartment containing an internal combustion engine and a cooler compartment adjacent the engine compartment containing a heat exchanger. The engine and cooler compartments have an opening defined therebetween. A forced air system is operable to drive an airflow. A method for cooling the engine and its compartment is disclosed.

An engine assembly includes an engine compartment containing an internal combustion engine and a cooler compartment adjacent the engine compartment containing a heat exchanger. The engine and cooler compartments have an opening defined therebetween. A forced air system is operable to drive an airflow. A method for cooling the engine and its compartment is disclosed.

An inlet assembly for an auxiliary power unit for an aircraft, including a particle separator and a plenum having first and second inlets. A first duct configured to deliver air to an engine of the auxiliary power unit is in fluid communication with an outlet of the plenum. A second duct configured to deliver air to a compartment containing the auxiliary power unit is in fluid communication with the outlet of the plenum. The assembly is selectively configurable between a first configuration where the plenum is in fluid communication with the environment of the aircraft through the second inlet and through the particle separator, and a second configuration where the plenum is in fluid communication with the environment of the aircraft through the first inlet independently of the particle separator. An auxiliary power unit assembly and a method of feeding air to an auxiliary power unit assembly are also discussed.

An inlet assembly for an auxiliary power unit for an aircraft, including a duct configured to provide fluid communication from an environment of the aircraft to an inlet of an engine of the auxiliary power unit, and a filter received in and extending across the duct. The filter includes a first filter portion permeable to air, positioned across only part of the duct and defining a transverse edge in the duct; a second filter portion permeable to air and extending from the transverse edge to an end downstream of the transverse edge, and a collection member impermeable to water. The collection member extends between the downstream end and a duct wall. The first and second filter portions are non-parallel and the second filter portion and the collection member are non-parallel. An auxiliary power unit assembly and a method of feeding air to an internal combustion engine are also discussed.

An engine assembly includes an engine compartment containing an internal combustion engine and a cooler compartment adjacent the engine compartment containing a heat exchanger. The engine and cooler compartments have an opening defined therebetween. A forced air system is operable to drive an airflow. A method for cooling the engine and its compartment is disclosed.