Inverse design of shock wave distortion for a direct-connect facility

Direct-connect facilities are very important experimental equipment for studying scramjets that have become the primary focus of research on hypersonic aircraft. Because of its short research cycle, minimal investment, and high revenue, this type of facility is used to conduct measurements in isolator/combustor studies. The principal function of the facility is to reproduce the distortions generated by the scramjet inlet during free jet experiments or flight tests. Many researches consider that the shock wave is the crucial factor influencing distortion. In this study, which is based on the Method of Characteristics (MOC), direct simulation of the shock wave distortion is presented. After specification of the parameters of the target line across the shock wave, the shock wave and flow path of the facility can be generated using the code based on MOC. The details of the design philosophy are described and the robustness and accuracy of the proposed method are verified in two cases with the aid of computational fluid dynamics. Finally, a specific facility is designed according to the proposed method. The relative errors of the Mach number and pressure are small enough to satisfy the requirements of the experiments. The facility also utilizes the expansion concept proposed by the authors in a previous study to address the starting problem successfully.