Numerical study on the influence of model scale and inflow conditions in wind tunnel experiment

An analysis was conducted for the aerodynamic relation of hypersonic integrated vehicle between real flight and wind tunnel conditions with numerical simulations,the commercially CFD code CFDFastran was used for the present calculations,the lift,drag and pitching moment of the vehicle were calculated by integrating the wall surface pressure and friction.The Mach number and static pressure in the wind tunnel were the same as real flight,but the total enthalpy and model scale were different.The CFD results were used to access effects of model scale and air flow conditions on the vehicle overall aerodynamic performance.It indicated that the main difference of the drag coefficient between full scale model,subscale model and that between wind tunnel test condition and flight test condition when the cowl door was opened,was the difference of friction drag coefficient of the engine inner flow path.These results provide reference for the correction of wind tunnel experimental data.