Hypersonic air intake design using multi-objective optimisation based on CFD data

The present study provides a numerical optimisation strategy for automatic design of the cowl lip and ramps of hypersonic inlets. A Reynolds-Averaged Navier-Stokes system of equations is used to validate the model in terms of global an local quantities respect to the experimental and literature results. Grid resolution and turbulence model sensitivity is performed revealing the minimum mesh size of 300k and the k − ω SST was the best settings for a good compromise between calculation time and accuracy. The new inlet shapes are determined with the usage of different goals: the minimisation of the drag coefficient and the maximisation of static and total compression ratios. The first goal is obtained with a shape with minor interference possible to the overall inlet, while the others two objectives are obtained with the disappearance of the normal shock in favour to the gradual compression generated by different oblique shocks.