NUMERICAL INVESTIGATION ON ENGINE INLET DISTORTION UNDER CROSSWIND FOR A COMMERCIAL TRANSPORT AIRCRAFT

摘要

Inlet distortion can cause a decrease in theperformance of the commercial transportaircraft engines due to the stall and instabilitywhich would have significant impact to theeconomy and safety of the aircraft.Inlet distortion under crosswind for a highbypass ratio turbofan engine is numericallysimulated motivated by the need ofengine/airframe integration of a commercialtransport aircraft. The inlet flow field,characteristics and underlying flow physics areinvestigated. The investigation suggests that: Asudden increase in the distortion index occursas the onset of the internal flow separation;Inlet distortion will deteriorate with increasingcrosswind speed. Flow separations,reattachments and ground vortex are found tobe the root causes for the crosswind distortion.When ground effect is taken into account, it willlead to inlet distortion and its effect willintensified with higher crosswind. The toleranceof crosswind would be reduced as the flowfieldaffected by the ground vortex phenomenon. Theresults and methods provide credibility whichwill technically benefit the engine/airframeintegration, experiments as well ascorresponding flight tests.