Preliminary Study by Means of Second-Order Closure of the Heat Transfer to a Porous Sphere/Cone. Effects of Surface Roughness, Edge Turbulence and Transpiration.

Abstract : A compressible second-order closure code for calulating the behavior of boundary layers on blunt axisymmetric bodies at zero angle of attack has been developed. The code is capable of calculating these boundary layers both with and without rotation and both with and without surface mass injection. Preliminary calculations have been made with the code to compare with NSWC measurements on a sphere/cone body at M = 5 and Reynolds numbers per foot of 3.8 million and 17.6 million. The effects of surface roughness and edge turbulence have been investigated. The initial theoretical predictions from the code are in good agreement with the experimental results. The results are dependent on the choices for the surface roughness and the edge turbulence parameters and it appears that a more extensive parametric search could lead to even better agreement with the experimental data. (Author)