51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013
JAN 07-10, 2013
Grapevine, TX, United states
To minimize the peak heat-flux of hypersonic blunt leading-edge, the Mini-Max optimization model is introduced for the first time for aerothermodynamics optimization. The surface heat-flux is obtained by resolving Navier-Stokes equations, and only the frozen flow is considered. The computational fluid dynamics (CFD) based Genetic Algorithm is used as the optimizer. A novel 2-D profile of leading-edge is obtained and the peak heat-flux is significantly reduced. Compared to the commonly used circular leading-edge, there is a large area of high temperature, high pressure in the front part of leading-edge, together with greater shock stand-off distance. The thickness of thermal boundary layer is increased about 40% at the stagnation point, the peak heat-flux is decreased about 20% and the heat-flux distribution is little changed in the vicinity of stagnation point. The robustness analysis shows that the favorable performance of the optimal 2-D profile is universally effective, i.e., it can effectively decrease the peak heat-flux by about 20% for various wall temperatures, Mach numbers, flight altitudes and thicknesses of the leading-edge as compared with the corresponding case of circular leading-edge. Although the reduction scope of peak heat-flux decreases with the change of angle-of-attack, but the peak heat-flux can still be decreased by more than 4% when the angle-of-attack is not greater than 15°. Several axisymmetric cases are also investigated in this paper, and the circular cone is taken as the benchmark, the peak heat-flux around an axisymmetric blunt cone, which is generated by the corresponding optimal 2-D profile, is also reduced by about 25%. Similarly, the distribution of heat-flux around the stagnation point is almost unchanged.
American Institute for Aeronautics and Astronautics (AIAA)