Shape optimization of an axisymmetric blunt body in hypersonic flow for reducing drag and heat transfer

A large design concern for high-speed vehicles such as next generation launch vehicles or reusable spacecraft is the drag and heat transfer experienced at hypersonic velocities. In this paper, the optimized shapes for minimum drag and heat transfer for an axisymmetric blunt body are developed using computational fluid dynamics (CFD) software in conjunction with a genetic algorithm (GA). For flow field calculations, the commercial flow solver ANSYS FLUENT is employed to solve the unsteady compressible Reynolds Averaged Navier-Stokes (RANS) equations in conjunction with the SST k-ω turbulence model. The hypersonic body shape is optimized using a multi-objective genetic algorithm (MOGA) to minimize both the drag and heat transfer. The MOGA creates a Pareto-optimal front containing the optimized shapes for various relative objectives of minimization of drag versus heat transfer. The results show a significant decrease in both the drag and heat transfer and exhibit the expected changes in the body profile. It should be noted that such results on shape optimization of a blunt body in hypersonic flow for reducing both drag and heat flux are reported in this paper for the first time in the literature. The proposed methodology will allow the simulation and optimization of more complex shapes for hypersonic vehicles.