火花型合成射流控制运输机后体流动分离的数值研究

利用火花型合成射流对运输机后体流动分离进行了主动控制的数值研究。研究结果表明:火花型合成射流一方面直接向边界层分离区域输入高能动量，另一方面与外流相互作用后形成的旋涡强化了高速外流和低速边界层流的混合，从而推迟了运输机后体的流动分离，减小了分离区的大小；在相同的合成射流激励参数下，在边界层分离点处以及分离点后施加主动控制后的作用效果更好，平均阻力系数最大减小3.26%；与当量的定常射流、脉冲射流相比较，脉冲射流减阻效果优于定常射流，火花型合成射流优于脉冲射流。 

Numerical study on transport aircraft after-body flow separation control by spark jet

Flow active control on transport aircraft after-body flow separation by the spark jet was numerically studied. The results show that the spark jet directly supplied the high-energy momentum to the boundary layer of the separation zone. Vortices induced by spark jet strengthened the mixing between the high-speed main flow and the low-speed boundary flow. It delayed the separation of the after-body flow and reduced the size of the separation zone. Under the same spark jet parameters, the effect of active control was better when the spark jet was led into the boundary layer at the position of the separation point or the downstream separation point. The average drag coefficient was reduced to 3.26%. Compared with the mass equivalent steady jet, pulsed jet and the pulsed jet had better performance on drag reduction than the steady jet. The spark jet was superior to the pulsed jet on drag reduction.