Error analysis of lateral jet interaction flow field of supersonic vehicle with traditional numerical method

With CFD method, the lateral jet interaction flow fields in supersonic cross-flows were simulated under real nozzle boundary condition and simplified nozzle boundary condition respectively. Three-dimensional N-S equations closed with k-ε turbulence model were solved and the unstructured grids were used to process spatial discretization for the flow field. By comparison, the calculated values were in good agreement with the experimental results, validating the numerical method. Further study showed that the boundary conditions had an effect on the lateral jet interaction flow field. Compared with the simplified nozzle boundary condition, due to the nonuniformity of the jet flow field at the nozzle exit, the separation vortex and the shock waves under real nozzle boundary condition moved forwards, thus causing the change of the interaction force and moment. Because of the influence of the frictions, the static thrust of the nozzle under the real nozzle boundary condition had a loss. When the pressure ratio was 500, the errors of the total normal force and total pitching moment between these two boundary conditions were 8.21% and 22.4% respectively, the errors were large. The real nozzle boundary should be considered when simulating the lateral jet interaction flow field accurately.