S弯进气道隐身设计中截面积和中心线影响

Based on the conformal inlet’s size requirement of flying wing unmanned aerial vehicle (UAV), s-shaped inlets are designed with super-ellipse equation, and they are also designed in three typical centerline and area distributions of “beginning fast and end slow”, “beginning and end the same”, and “beginning slow and end fast”. The numerical simulation is verified on electromagnetic scattering characteristics of the inlet with straight cavity based on multilevel fast multipole method (MLFMM), and the stealth analysis is also carried out. And then the mechanism is analyzed combining with electric current distribution. Results indicate that with the inlet terminator open, there is little difference of the stealth characteristics on different centerline and area distributions; the centerline distribution exerts greater influence than the area distribution on the stealth characteristics of inlet; adopting the centerline distribution of “beginning fast and end slow” and area distribution of “beginning and end the same” in the s-shaped inlet designs lead to both good aerodynamic and stealth performance.