Combined modeling technology for external flow field of wide-speed supersonic/hypersonic vehicles

Fast aerodynamic estimation is one of the key technologies for performance evaluation and optimization design in the preliminary design phase of the aircraft. It requires a balance between the calculation accuracy and calculation speed. This study aimed to establish a fast aerodynamic estimation combined model in the wide-speed domain and design fast aerodynamic estimation software based on the mechanistic theory and engineering model. First, a combined calculation model for pressure along the streamline was established based on the shock wave theory, expansion wave theory, modified Newton's theory, and so forth. Further, the combined calculation model for friction along the streamline was constructed based on the van Driest II theory and plate boundary layer theory. Second, the HL-20 lift body of the Langley Research Center was taken as the research object, and the results of the model were compared with high-precision computational fluid dynamics (CFD) data for verification. The results showed that the established model was in good agreement with CFD calculation results. Finally, combined wide-speed domain aerodynamic model and a rapid estimation platform (aerodynamic force preliminary evaluation, AFPE) independent of the calculation object was developed based on the streamline tracking technology and compared with the experimental data in the open literature. The results showed that AFPE had an excellent reproducibility of test data and an acceptable calculation speed in working ranges with relatively large Mach numbers, providing tool support for hypersonic aircraft high-speed aerodynamic estimation.