28th International Symposium on Rarefied Gas Dynamics (RGD)
JUL 09-13, 2012
Hypersonic flow over a flat plate is investigated under a wide range of Mach and Knudsen numbers using both continuum-based approach and DSMC method. The simulated gas is argon thus to isolate the high temperature effects. The Mach number of the flow lies between 5 and 30 whereas the Knudsen number covers the entire flow regime. It is learned that local rarefaction is observed near the leading edge even when the Knudsen number is around 0.001. The continuum breakdown can be identified using a nonequilibrium parameter that evaluates the difference among the temperature components. It is also learned that there is competition between viscous effects and rarefied effects on the skin friction. The total drag on the plate can be well estimated using a bridging formula that connects the results from the continuum and free molecular expressions. In addition, the value of drag depends on the surface temperature. The drag coefficient increases with the surface temperature when the Knudsen number is less than 0.01 but decreases when the Knudsen number is larger than 1.0.
Hu Y,Chen S,Sun QH,et al. Hypersonic aerodynamics of a flat plate: bridging formula and wall temperature effects[C]28TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS 2012, VOLS. 1 AND 2,2012:1493-1499.