초록 ▼

Within a turbine engine a heat exchanger may be provided to cool compressor air flows to be utilized for cabin ventilation or other functions. A fluid flow acting as a coolant for the heat exchanger is generally drawn from the by-pass duct of the engine and a dedicated outlet duct is provided such t

Within a turbine engine a heat exchanger may be provided to cool compressor air flows to be utilized for cabin ventilation or other functions. A fluid flow acting as a coolant for the heat exchanger is generally drawn from the by-pass duct of the engine and a dedicated outlet duct is provided such that the exhausted fluid flow from the heat exchanger is delivered along the conduit duct to a low pressure region. In such circumstances, an appropriate pressure differential across the heat exchanger is maintained for operational efficiency when required, whilst the exhausted fluid flow is isolated and does not compromise the usual engine ventilation vent exit area sizing. Over-sized ventilation vents would create an aerodynamic step and therefore drag upon the thrust of the engine. Typically, the outlet end of the outlet duct has a variable geometry to enable adjustment in the pressure differential across the heat exchanger such that an air fan valve used to control flow rate through the heat exchanger may not be required.

대표청구항 ▼

We claim: 1. A gas turbine engine comprising:a heat exchanger having an outlet duct for a coolant fluid flow passing therethrough during operation of the engine;a by-pass duct having an exit plane; anda ventilation zone defined between a core cowl and an outer cowling, said ventilation zone having a

We claim: 1. A gas turbine engine comprising:a heat exchanger having an outlet duct for a coolant fluid flow passing therethrough during operation of the engine;a by-pass duct having an exit plane; anda ventilation zone defined between a core cowl and an outer cowling, said ventilation zone having a ventilation fluid flow therethrough during operation of the engine and a vent slot sized for said ventilation fluid flow alone, said heat exchanger outlet duct extending to an outlet end in said outer cowling downstream of said by-pass duct exit plane, said ventilation fluid flow and said coolant fluid flow being separate, wherein said heat exchanger outlet duct has a variable geometry nozzle to optimize static pressure reduction and therefore control fluid flow through said heat exchanger during operation of the engine.