Aero-Optical Characteristics of Supersonic Flow over Blunt Wedge with Cavity Window  

作　　者：李波 刘洪 

机构地区：[1]School of Naval Architecture,Ocean and Civil Engineering [2]School of Aeronautics and Astronautics,Shanghai Jiaotong University

出　　处：《Journal of Shanghai Jiaotong university(Science)》2011年第6期742-749,共8页上海交通大学学报（英文版）

摘　　要：The optical rays that form the image of an object and propagate a supersonic flow over a vehicle are refracted by the density variations.A numerical analysis of the aero-optical characteristics of supersonic flow over blunt wedge with a cavity window is carried out.A hybrid method of Reynold averaged Navier-Stokes and direct simulation Monte Carlo(RANS/DSMC) is employed to simulate the flowfield.Refraction factor is introduced to evaluate the flowfield's aero-optical characteristic.The results show that mean flow's aero-optical effects are mainly caused by the shock wave,the expansion wave and the turbulent boundary layer.Fluctuation flow's aero-optical effects are mainly caused by the turbulent boundary layer and the shock wave induced by the cavity window.The aero-optical effects at the leading side of window are caused by the mean density variations,while the effects at the trailing side are caused by the density fluctuations.Different draft angles of the cavity window are investigated.The airborne optical devices of supersonic vehicle should be mounted in the middle of the cavity window with a large draft angle.The optical rays that form the image of an object and propagate a supersonic flow over a vehicle arc refracted by the density variations. A numerical analysis of the aero-optical characteristics of supersonic flow over blunt wedge with a cavity window is carried out. A hybrid method of Reynold averaged Navier-Stokes and direct simulation Monte Carlo （RANS/DSMC） is employed to simulate the flowfield. Refraction factor is introduced to evaluate the flowfield＇s aero-optical characteristic. The results show that mean flow＇s aero-optical effects arc mainly caused by the shock wave, the expansion wave and the turbulent boundary layer. Fluctuation flow＇s aero-optical effects are mainly caused by the turbulent boundary layer and the shock wave induced by the cavity window. The aero-optical effects at the leading side of window are caused by the mean density w^riations, while the effects at the trailing side are caused by the density fluctuations. Different draft angles of the cavity window are investigated. The airborne optical devices of supersonic vehicle should be mounted in the middle of the cavity window with a large draft angle.

关 键 词：AERO-OPTICS supersonic flow blunted wedge cavity window 

分 类 号：O439[机械工程—光学工程] V21[理学—光学]