Multiobjective Design Optimization of Hypersonic Combinational Novel Cavity and Opposing Jet Concept

Abstract

It attaches profound importance to conduct a survey on drag reduction and a thermal protection mechanism applied to the nose tip of hypersonic reentry vehicle due to severe aerodynamic drag and heating. The combinational forward-facing cavity and opposing jet configuration is an effective concept, and its performance could be partially improved when a maximum thrust nozzle contour is employed to substitute the conventional cavity configuration. However, the novel concept would not necessarily generate higher drag and heat reduction efficiency than the conventional one. Therefore, based on the verification of a numerical method, multiobjective design optimization of the combinational novel cavity and opposing jet concept is conducted to minimize both the drag force coefficient and heat load in the current study. The jet total pressure ratio and geometric dimensions are selected as design variables, and the sampling points are obtained numerically by using an optimal Latin hypercube design method. The multi-island genetic algorithm coupled with the kriging surrogate model integrated in Isight 5.5 has been employed to establish the approximate model and solve the Pareto-optimal front. The operating conditions located on the front are proved accurate by a computational fluid dynamics method, and higher drag and heat reduction efficiency can be realized than the conventional configuration at a relatively lower jet total pressure.