A series of axisymmetric vectoring nozzles with different divergent geometrical parameters were studied based on 3D numerical simulations

and each nozzle's flow field was simulated under different working conditions. The effects of divergent angle and divergent wall length on nozzle performance were analyzed. Through the method of least square surface fitting

a mathematical model taking divergent angle

divergent length/throat height

nozzle pressure ratio/designed nozzle pressure ratio and vector angle as its independent variables was established. Through comparison of performance predictions with the experimental data

result showed that

the error of thrust coefficient was under 0.41%

the error of flow coefficient was under 1.58% and the error of vectoring angle was under 1.76°. The mathematical model was built to predict performances of nozzle with different geometrical parameters

presenting strong commonality and engineering significance.