Robust Aeroelastic Design Optimization of Hypersonic Wings Considering Uncertainty in Heat Flux

A robust aeroelastic optimization design methodology for hypersonic wings considering uncertainty in heat flux is presented and applied to a design process of a typical hypersonic low-aspect-ratio wing. An interval analysis method is used to perform the transient heat transfer analysis with uncertainty in heat flux within the newly developed aerothermoelastic framework. A genetic algorithm is used to build the framework for robust optimization, and it is also used to determine the critical thermal load case from an interval temperature field obtained using interval heat transfer analysis. Aerothermoelastic analysis of the hypersonic wing shows that the structure may bear a severely worsening thermal environment when there is uncertainty in heat flux during hypersonic flight. Not merely the average temperature, but also the temperature gradient distribution of the structure rises, which might make designs created using deterministic analysis methods unreliable. Optimization results show that the robust optimization design methodology can provide a relatively light structural design and simultaneously make sure it is capable of satisfying multiple constraints under severe thermal environments with uncertainty.