Hypersonic Turbulent Flow Simulation of FIRE II Reentry Vehicle Afterbody
This paper presents a numerical investigation of the hypersonic reacting flow around the FIRE II reentry capsule. At the
chosen freestream conditions, the forebody boundary layer and the separated flow on the afterbody are turbulent. The
Reynolds-averaged NavierStokes method along with two commonly used turbulence models are used to compute the flowfield.
Accurate prediction of turbulent separated flow at hypersonic conditions is challenging due to the limitations of the
underlying turbulence models. The presence of turbulent eddy viscosity in the flow simulation results in a smaller
separation bubble than the laminar solution at identical conditions. Also, the two turbulence models predict different
levels of eddy viscosity in the neck region. This has a dominant effect on the separation bubble size and the surface
pressure. On the other hand, the eddy viscosity values in the near-wall region determine the heat transfer rate to the
body. The two models predict comparable heating rates on the conical frustum, and the results match in-flight measurement
well. By comparison, surface pressure predictions are appreciably higher than the data.
Ref: Reddy, D.S.K., and Sinha, K., "Hypersonic turbulent flow simulation of FIRE II re-entry vehicle afterbody", Journal of Spacecrafts and Rockets, Vol. 46, No. 4, 2009.
Representative results:
Simuation of axisymmetric flow around the FIRE II re-entry capsule using five-species air chemistry and a perfect gas model.
Comparison of computed afterbody heat transfer rate with in-flight measurements for flow over the FIRE II capsule at 35 km altitude.