Numerical analysis and flow state prediction of double wedge steady/unsteady flow at different in flow

This paper focuses on the laminar interaction of shock waves and the phenomenon of steady/unsteady flow in the hypersonic double wedge flow. The different working conditions (Ma_∞ and Re) were selected for numerical simulation and flow characteristics research with the developed third-order WENO scheme; The variation patterns of shock wave structure and separation zone in steady/unsteady flow fields caused by parameter changes were summarized. Based on the least squares support vector machine (LS-SVM) model, we developed a steady/unsteady flow states prediction model for the double wedge flow using various kernel functions (linear, polynomial, and radial basis functions) in order to forecast the steady/unsteady flow states of the double wedge flow at various Ma_∞ and Re. Three prediction models were validated and evaluated on the validation set. With 16 working circumstances, the results demonstrate that the radial basis function prediction model is capable of successfully predicting every double wedge flow state. The accuracy and true positive rate of the prediction results are 1, and the false positive rate is 0. The prediction ability is the strongest and has better generalization ability. The polynomial kernel prediction model takes second place in prediction ability, and the linear kernel prediction model has the worst prediction ability.