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.