鸭翼展向吹气对发动机推力损失影响的评估

风洞实验结果表明鸭翼展向吹气能提高飞机大迎角升力,延缓机翼涡破裂,增大飞机失速迎角.但由于鸭翼展向吹气需从发动机引气,这势必对发动机推力和飞机的各项性能产生影响.采用动量定理和耗油率公式对从发动机引气造成的气流质量流量损失、发动机推力损失和对飞机总升力(引气造成的升力损失和鸭翼吹气获得的升力增量之和)的影响等方面进行了评估,并比较了机翼展向吹气与鸭翼展向吹气两种方式.结果表明,鸭翼展向吹气引气量少、推力损失小,对飞机大迎角机动性能有利,是一种可取的间接涡控制技术.

Evaluation of engine thrust loss for canard-spanwise blowing

The results of force measurement in low speed wind-tunnel show that canard-spanwise blowing can increase the lift of high angle of attack,delay the breakdown of wing vortex and enlarge the stalling angle of aircraft.But canard-spanwise blowing must bleed air from engine,which makes the engine thrust lost and affects the performance of aircraft.Two methods(theorem of momentum and formula of specific fuel consumption)were used to evaluate the mass loss of inlet air,engine thrust loss,and total lift of aircraft(the sum of lost lift by bleed air form engine and the increased lift by canard-spanwise blowing).The effect of canard-spanwise blowing was compared with that of the wing-spanwise blowing.It indicates that canard-spanwise blowing needs less mass of air-bleed,with fewer thrust loss and can improve the maneuverability at high angles of attack.So it is advisable that canard-spanwise blowing is an indirect vortex control technique in the future.