Aerothermodynamic Sensitivity Analysis and Optimization of Hypersonic Reentry Vehicle

The complicated real gas effects occurring at hypersonic speeds influence the vehicle’s performance and design. Therefore, it is important to incorporate high-fidelity techniques, such as computational fluid dynamics (CFD), into the design and optimization process. This work builds a reliable and efficient gradient-based optimization approach that incorporates CFD using analytical sensitivity techniques. A shape optimization approach is developed using Bézier curves and radial basis functions to define the geometry. An intrusive analytical sensitivity analysis is developed to solve the sensitivity equations with a generalized minimum residual solver and leverages the line-implicit solver employed in the CFD to precondition the system. This technique is applied to the geometry of a hypersonic reentry vehicle, IRV-2, to reduce the drag without increasing the pressure, heat flux, or total surface heat transfer rate into the vehicle. This research considers the shape of the entire vehicle and produces a reduction in total vehicle drag of up to 5.7%. The optimization is performed at three IRV-2 trajectory points, individually, to understand the influence of flight conditions on the optimized design. Although the lower altitude optimized designs produce a smaller reduction in drag, they consistently reduce drag when evaluated along the first portion of the trajectory.