Relationship between the Actual Entry of Vehicles into the Martian Atmosphere and Its Simulation in a Wind Tunnel Using Mars Entry Vehicles of Various Geometries

抄録

Owing to certain limitations of wind tunnel experiments, it is difficult to obtain the real flight flow field of a vehicle entering the Martian atmosphere using wind tunnel data. Consequently, it is necessary to establish a correlation between simulation of the entry of a vehicle into the Martian atmosphere using a wind tunnel and the actual entry of a vehicle into the Martian atmosphere. In this investigation, a numerical method and a comparative analysis are utilized to explore the application of data from wind tunnel experiments to the actual entry of vehicles with representative geometries (excluding the Mars Pathfinder) into the Martian atmosphere. The results of the comparative analysis demonstrate that, if the same double-scale parameters are used for existing reentry vehicles with various geometries, the pressure coefficient and dimensionless pressure near the stagnation point of a low-enthalpy wind tunnel (using air with a composition similar to that of Earth's atmosphere) can be applied to directly extrapolate the experimental parameters of the wind tunnel to the actual aircraft flow field parameters of the Martian atmosphere. In the case of high-enthalpy wind tunnels using air with a composition similar to that of Earth’s atmosphere and those using CO₂, the pressure coefficient and dimensionless pressure near the stagnation point can be used as the extrapolation parameters; however, the Stanton number and dimensionless heat flow cannot be directly used as extrapolation parameters.