A gas turbine engine including an engine core with a duct, nacelle, and bypass duct receiving fan-accelerated bypass air flow. The core duct is located radially inside the bypass duct and receives the core air flow. A housing between the core and bypass ducts has an outer wall, which is the bypass duct inner wall, and inner wall which is core duct outer wall. The housing extends axially from the gas turbine engine, and splits fan accelerated air flow axially forward into the bypass and core ducts. At least two heat exchangers for cooling engine based oil are mounted in the housing. A flow passage inside the housing delivers air flow to the heat exchangers, and returns air flow from the heat exchangers. The at least two heat exchangers extend circumferentially, and a flow divider is between the heat exchanger ends and diverts air flow to the heat exchangers.

A gas turbine engine including an engine core with a duct, nacelle, and bypass duct receiving fan-accelerated bypass air flow. The core duct is located radially inside the bypass duct and receives the core air flow. A housing between the core and bypass ducts has an outer wall, which is the bypass duct inner wall, and inner wall which is core duct outer wall. The housing extends axially from the gas turbine engine, and splits fan accelerated air flow axially forward into the bypass and core ducts. At least two heat exchangers for cooling engine based oil are mounted in the housing. A flow passage inside the housing delivers air flow to the heat exchangers, and returns air flow from the heat exchangers. The at least two heat exchangers extend circumferentially, and a flow divider is between the heat exchanger ends and diverts air flow to the heat exchangers.

An oil tank for a gas turbine engine is provided. The oil tank includes an oil cavity defined within structural walls of a nacelle of the gas turbine engine, the oil cavity having an oil inlet and an oil outlet. At least one of the structural walls has an interior side facing the oil cavity and an exterior side. The interior side includes a plurality of upstanding protrusions extending into the oil cavity and fully immersed in oil when the gas turbine engine is in use during steady state operation. The exterior side includes a plurality of fins extending therefrom and exposed to an ambient air stream during steady state operation of the gas turbine engine.

An oil tank for a gas turbine engine is provided. The oil tank includes an oil cavity defined within structural walls of a nacelle of the gas turbine engine, the oil cavity having an oil inlet and an oil outlet. At least one of the structural walls has an interior side facing the oil cavity and an exterior side. The interior side includes a plurality of upstanding protrusions extending into the oil cavity and fully immersed in oil when the gas turbine engine is in use during steady state operation. The exterior side includes a plurality of fins extending therefrom and exposed to an ambient air stream during steady state operation of the gas turbine engine.

An oil cooling system for an aircraft engine, a bypass valve and an associate method of cooling aircraft engine oil are provided. The oil cooling system includes a heat exchanger having an inlet and an outlet. The inlet is in fluid communication with a first oil conduit to receive a first oil flow from the first oil conduit. The heat exchanger facilitates heat transfer from the first oil flow to another fluid. A flow restrictor defining a constriction is operatively disposed to restrict the first oil flow through the heat exchanger. A second oil conduit receives the first oil flow from the heat exchanger. A bypass oil passage provides fluid communication between the first oil conduit and the second oil conduit to allow a second oil flow received from the first oil conduit to flow to the second oil conduit and bypass the heat exchanger.

An oil cooling system for an aircraft engine, a bypass valve and an associate method of cooling aircraft engine oil are provided. The oil cooling system includes a heat exchanger having an inlet and an outlet. The inlet is in fluid communication with a first oil conduit to receive a first oil flow from the first oil conduit. The heat exchanger facilitates heat transfer from the first oil flow to another fluid. A flow restrictor defining a constriction is operatively disposed to restrict the first oil flow through the heat exchanger. A second oil conduit receives the first oil flow from the heat exchanger. A bypass oil passage provides fluid communication between the first oil conduit and the second oil conduit to allow a second oil flow received from the first oil conduit to flow to the second oil conduit and bypass the heat exchanger.

The gas turbine engine can have an air mover configured for generating a flow of air around a rotation axis; a surface extending around the rotation axis delimiting a passage for the flow of air downstream of the air mover; an electric machine disposed within the passage and coupled to the air mover; a coolant circuit having: an evaporator circumferentially disposed around at least part of the electric machine and in thermal communication therewith; a condenser having a surface cooler circumferentially disposed at least partially around the surface and in thermal communication therewith; a first conduit fluidly connecting an upper region of the evaporator to an upper region of the condenser; and a second conduit fluidly connecting a lower region of the condenser to a lower region of the evaporator; and a coolant fluid in the coolant circuit.

An oil system, has: a pump driving an oil flow in an oil conduit, the pump having an outlet pump pressure; a heat exchanger providing heat exchange between the oil flow and one or more fluid; a component downstream of the heat exchanger, the component having a maximum oil pressure requirement and a minimum oil pressure requirement; and a flow restrictor in fluid flow communication with the oil conduit, the flow restrictor having an orifice sized to provide a restrictor pressure differential across the flow restrictor, the restrictor pressure differential being equal to at least the outlet pump pressure minus pressure differentials through the heat exchanger and the oil conduit from an outlet of the pump to the component minus the maximum oil pressure requirement, and at most the outlet pump pressure minus the pressure differentials through the heat exchanger and the oil conduit minus the minimum oil pressure requirement.

An oil system, has: a pump driving an oil flow in an oil conduit, the pump having an outlet pump pressure; a heat exchanger providing heat exchange between the oil flow and one or more fluid; a component downstream of the heat exchanger, the component having a maximum oil pressure requirement and a minimum oil pressure requirement; and a flow restrictor in fluid flow communication with the oil conduit, the flow restrictor having an orifice sized to provide a restrictor pressure differential across the flow restrictor, the restrictor pressure differential being equal to at least the outlet pump pressure minus pressure differentials through the heat exchanger and the oil conduit from an outlet of the pump to the component minus the maximum oil pressure requirement, and at most the outlet pump pressure minus the pressure differentials through the heat exchanger and the oil conduit minus the minimum oil pressure requirement.

A system and method are disclosed for cooling ambient air to be supplied as combustion air to a gas turbine. The system comprises a closed coolant loop direct expansion cooling system including a compressor for compressing a suitable working fluid, an expansion device downstream from the compressor for expanding the working fluid so as to cool a cooling coil. The cooling coil is in heat exchange relation with ambient air flowing to the gas turbine for lowering the temperature of the ambient air to a lower temperature such that combustion air delivered to the gas turbine is below the ambient temperature thereby to increase the efficiency of the gas turbine. A return line is provided for returning the working fluid to the compressor.