背负式S形进气道设计及数值分析

针对无人机布局特点，设计了一种短扩压、大偏距、背负式S形进气道。设计中采用变厚度唇口技术，两曲面相贯构造斜切进口技术，并对前人提出的扩压器中心线方程和面积变化规律进行了改进。利用计算流体力学（CFD）方法分析了S形进气道的内流特性及机身对S形进气道性能的影响。此外，作为验证，进行了进气道与发动机的地面试验，数值计算与试验结果都表明，S形进气道具有较好的气动特性，有一定工程应用价值。

Design and numerical investigation of dorsal S-shaped inlet

According to the layout characteristics of UAV(unmanned air vehicle) platform,a dorsal subsonic S-shaped inlet with short diffuser and large offset is designed.In the process of the design,two curved surfaces are intersected to make the scarf lip which the thickness varies;new center line and area regularity(duct curvature and cross section) are created.By using CFD software flow characteristics of S-shaped inlet are analyzed.Furthermore,the effect of fuselage on the inlet by means of the angle of attack is given.Test under takeoff condition is designed to verify the inlet performance.The results show that the S-shaped inlet has good performance and the design project meets the design requirements primarily.