PREDICTION OF SHOCK INTERFERENCE FLOW FIELD STRUCTURE BASED ON THE MULTI-LEVEL BLOCK BUILDING ALGORITHM

Shock-shock interference flow flied prediction is one of the most challenging problems in supersonic flow and even hypersonic flow. In particular, type IV shock interference has attracted more and more attention due to the extremely high thermal loads it generates in the vicinity of stagnation point. In this paper, we analyze meticulously the effect of high temperature gas effects on the geometric structure of the shock interference and the flow field parameters, especially of the type IV shock interference, based on the calorimetric perfect gas model and the thermal perfect gas model considering only vibration excitation, respectively, by numerically solving the viscous two-dimensional compressible Navier-Stokes equations for the cylindrical-induced bow shock wave and oblique shock wave interference problems. With the increase of free stream Mach number, the effect of high-temperature gas is gradually significant. And then, based on a new genetic algorithm with generalized separability (multi-level block building algorithm), mathematical models that can predict the characteristic geometric structures such as the location of the triple wave point and the geometry of the supersonic jet in the type IV interference under different gas models are presented to obtain a quantitative assessment of the effect of high temperature gas effects on the transition criterion for the type of interference for thermal protection work. The comparison results of the radical interference structure and wall pressure and wall heat flux distribution for multiple sets of critical conditions on the transition criterion surface show that the interference types and flow field structures under different gas models differ significantly, and the obtained quantitative prediction model has certain reference value for the prediction of aerodynamic thermal environment in practical engineering applications. In the end, multiple sets of critical working conditions on the transition criterion surfaces are used to prove it, revealing the engineering significance of the criteria.