Rapid Assessment on Flow Parameter Matching Scheme in Aerodynamic Testing in a Combustion Wind Tunnel

A rapid assessment on matching schemes of nozzle flow parameter of a combustion wind tunnel is carried out based on fundamental aerodynamics. Shock and isentropic compression configurations are introduced to quantify the deviation range of the aerodynamic characteristics with respect to the true flight under multiple matching conditions. It is found that, when the flow Mach number is simulated, the deviations of aerodynamic forces with shock compression are less than 2 %, but the mismatch of the wave structures can be significant. When the total pressure and the dynamic pressure are simultaneously simulated instead, both aerodynamic forces and wave structures can be well reproduced. Numerical simulation of the flow over a more practical configuration confirms the results of rapid assessment. The simulation also indicates that with an appropriate flow matching scheme combustion wind tunnel can reproduce the aerodynamic characteristics closer to true flight than conventional ones.