The Aerodynamic Characteristics Research Of Top-mounted S-shaped Inlet Based On The Comparison Of Two Different Entrance Shape

A new design concept of the jet engine inlet based on unmanned stealthaircraft design requirements and traditional inlet design method, as well asCFD simulations results of two different designs, are presented in this paper.CFD modeling is used to simulate the aerodynamic behaviour of S–shapedinlets based on two different entrance geometries. In this paper, kinetic energyratio between the mainstream and the secondary flow as a new distortionindex to evaluate the flow distortion is proposed,aiming at the vortices of thesecondary flow in the flow field of the S-shaped inlet.The inlet performance analysis (under equal flight conditions) showedthat the crosswise cut entrance shaped inlet has better performances than thevertical cut entrance shaped inlet in both the total pressure recoverycoefficient and the total pressure distortion coefficient,but poorperformances in the swirl distortion coefficient.The symmetrical vortex distribution structure of the outlet is influencedby the yaw angle, which is the main factor that caused flow distortion.Experiments carried out on the prototype showed that S-shaped inletdesigned in the present study matches well the engine. The design isconsidered successful and the CFD model accurate.