Abstract: A controlled gap seal device is adapted to surround a shaft with an annular seal element. A ring is positioned on an outer surface of the seal element, the ring adapted to modify a diametrical dimension of the seal element by thermally expanding/contracting as a function of temperature variations. A housing assembly has an interior enclosing the seal element and the ring, with the seal configured to be generally stationary in the interior. The housing assembly has an air inlet and air outlet in fluid communication with a surrounding environment for directing a flow of gas from the surrounding environment onto the ring to controllably cool and shrink the ring. A method for modifying a diameter of a controlled gap seal relative to the shaft is also provided.

Abstract: A controlled gap seal device is adapted to surround a shaft with an annular seal element. A ring is positioned on an outer surface of the seal element, the ring adapted to modify a diametrical dimension of the seal element by thermally expanding/contracting as a function of temperature variations. A housing assembly has an interior enclosing the seal element and the ring, with the seal configured to be generally stationary in the interior. The housing assembly has an air inlet and air outlet in fluid communication with a surrounding environment for directing a flow of gas from the surrounding environment onto the ring to controllably cool and shrink the ring. A method for modifying a diameter of a controlled gap seal relative to the shaft is also provided.

Abstract: The combined cooling system uses a single heat exchanger to cool both engine air for use in an engine system and aircraft air for use in an aircraft system. More particularly, a bleed air path leads from the compressor stage to the heat exchanger where it is placed in thermal exchange contact with a flow of cooling air coming from a cooling path. From an outlet end of the heat exchanger, the bleed air splits into two paths: an aircraft air path leading to at least one aircraft system such as an Environmental control system (ECS), a wind de-icing system or the like, and an engine air path leading to at least one engine system such as a buffer air system for pressurizing the bearing cavities.

Abstract: A heat management system of a gas turbine engine for cooling oil and heating fuel, includes an oil circuit having parallel connected first and second branches. The first branch includes a fuel/oil heat exchanger and a first fixed restrictor in series and the second branch includes an air cooled oil cooler and a second fixed restrictor. The first and second fixed restrictors limit respective oil flows through the first and second branch differently, in response to viscosity changes of the oil caused by temperature changes of the oil during engine operation to modify oil distribution between the first and second branches.

Abstract: A heat management system of a gas turbine engine for cooling oil and heating fuel, includes an oil circuit having parallel connected first and second branches. The first branch includes a fuel/oil heat exchanger and a first fixed restrictor in series and the second branch includes an air cooled oil cooler and a second fixed restrictor. The first and second fixed restrictors limit respective oil flows through the first and second branch differently, in response to viscosity changes of the oil caused by temperature changes of the oil during engine operation to modify oil distribution between the first and second branches.

Abstract: A flow restrictor is provided for a lubrication circulation system. The flow restrictor comprises a body configured to obstruct a flow of lubricant within the lubricant circulation system. The body has one or more through holes communicating with upstream and downstream portions of the lubrication circulation system. Each of the one or more holes has a cross-sectional area sufficiently small, and a length sufficiently long, to prevent turbulent lubricant flow therethrough at temperatures below a first predetermined reference temperature. The one or more holes have sufficient aggregate cross-sectional area to allow a desired lubricant flow rate through the body at temperatures at or above a second predetermined reference temperature.

Abstract: A controlled gap seal device is adapted to surround a shaft with an annular seal element. A ring is positioned on an outer surface of the seal element, the ring adapted to modify a diametrical dimension of the seal element by thermally expanding/contracting as a function of temperature variations. A housing assembly has an interior enclosing the seal element and the ring, with the seal configured to be generally stationary in the interior. The housing assembly has an air inlet and air outlet in fluid communication with a surrounding environment for directing a flow of gas from the surrounding environment onto the ring to controllably cool and shrink the ring. A method for modifying a diameter of a controlled gap seal relative to the shaft is also provided.

Abstract: The combined cooling system uses a single heat exchanger to cool both engine air for use in an engine system and aircraft air for use in an aircraft system. More particularly, a bleed air path leads from the compressor stage to the heat exchanger where it is placed in thermal exchange contact with a flow of cooling air coming from a cooling path. From an outlet end of the heat exchanger, the bleed air splits into two paths: an aircraft air path leading to at least one aircraft system such as an Environmental control system (ECS), a wind de-icing system or the like, and an engine air path leading to at least one engine system such as a buffer air system for pressurizing the bearing cavities.

Abstract: A heat management system of a gas turbine engine for cooling oil and heating fuel, includes an oil circuit having parallel connected first and second branches. The first branch includes a fuel/oil heat exchanger and a first fixed restrictor in series and the second branch includes an air cooled oil cooler and a second fixed restrictor. The first and second fixed restrictors limit respective oil flows through the first and second branch differently, in response to viscosity changes of the oil caused by temperature changes of the oil during engine operation to modify oil distribution between the first and second branches.

Abstract: A gas turbine engine includes a fuel-oil heat exchange system in which the fuel is continuously heated by a primary hot oil flow in a primary fuel-oil heat exchanger and the fuel is selectively heated in a secondary fuel-oil heat exchanger by a secondary hot oil flow selectively passing through or bypassing a secondary fuel-oil heat exchanger, controlled by a thermal valve.

Abstract: A gas turbine engine includes a fuel-oil heat exchange system in which the fuel is continuously heated by a primary hot oil flow in a primary fuel-oil heat exchanger and the fuel is selectively heated in a secondary fuel-oil heat exchanger by a secondary hot oil flow selectively passing through or bypassing a secondary fuel-oil heat exchanger, controlled by a thermal valve.

Abstract: A flow restrictor is provided for a lubrication circulation system. The flow restrictor comprises a body configured to obstruct a flow of lubricant within the lubricant circulation system. The body has one or more through holes communicating with upstream and downstream portions of the lubrication circulation system. Each of the one or more holes has a cross-sectional area sufficiently small, and a length sufficiently long, to prevent turbulent lubricant flow therethrough at temperatures below a first predetermined reference temperature. The one or more holes have sufficient aggregate cross-sectional area to allow a desired lubricant flow rate through the body at temperatures at or above a second predetermined reference temperature.

Abstract: A method and apparatus for cooling a fluid in a bypass gas turbine engine involves directing the fluid to the bypass duct of the engine to allow for heat exchange from the fluid to bypass air passing through the bypass air duct.