Study on the Aerodynamic Characteristics of Top-Mounted Inlet with Different Lip Angles

Abstract

Abstract The stealthy performance is an important factor to be considered in the design of the modern UAV, and the inlet is the strong RCS scattering source, which needs to be paid more attention. The inlet with lip angle is beneficial to the stealth performance, but unfavorable to the aerodynamic characteristics of the inlet. In this paper, three inlets with different lip angles are studied, and the characteristics of the inlets are obtained by using CFD and experimental methods. Results indicate: 1) data obtained by CFD well predicts the vortex in the inlet, and it’s very close to the experimental value, which shows that CFD method can be used for analysis; 2) the lip angle has a great influence on the characteristics of the inlet under ground running, and the circumferential distortion index of the inlet increases rapidly with the increase of the lip angle; 3) the effects of the lip angle on the characteristics of the inlet can be ignored under the condition of the high incoming Mach number.