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.