Analysis of flow field characteristics of S-bend inlet with dual synthetic jets

S-bend inlet leads to obvious flow separation and apparent total pressure distortion in unmanned aerial vehicle. To solve this problems, an active flow control method based on dual synthetic jets was proposed accordingly. The numerical simulation model of S-bend inlet with dual synthetic jets was established. The results show that dual synthetic jets can effectively suppress the boundary layer flow separation near the separation point of S-bend inlet through "blowing" and "suctioning" in the whole jet cycle, and effectively improve the total pressure recovery coefficient. The effects of different jet angles, jet peak velocities and jet frequencies on the flow field control characteristics of S-bend inlet were studied. The results shows that the smaller the angle between the dual synthetic jet and the main stream is, the better the flow separation control effect will be. The larger jet peak velocity will form a "blocking" effect on the main stream, resulting in a decrease in control effect. The closer the jet frequency is to the characteristic frequency of the flow field, the more obvious the control effect will be.