Mathematical model analysis of axisymmetric nozzle performance prediction for complex system based on numerical simulation

When the convergent-divergent nozzle operates under the over expanded conditions, it can cause supersonic flow separation forming an attached oblique shock wave at the separation base. This asymmetric nature causes downstream instabilities. In order to predict and analyze the performance parameters of different axisymmetric vectoring nozzles with a unified model, the internal and external flow fields of different axisymmetric vectoring nozzles were studied. These studies were conducted under various working conditions by using three-dimensional numerical simulation method. The objective of this article is to study the numerical analysis for visualizing the fluid flow and characteristics of thermal axisymmetric nozzle. The curve fitting approach is considered as the designed methodology. The experimental analysis provides a better learning for improving the methodology. The performance of proposed design has shown a significant improvement and the presented nozzle has a tremendous effect on the behavior of fluid flow. A multivariable mathematical model for predicting the performance of axisymmetric vectoring nozzle with independent variables including expansion angle, length, throat diameter, drop to pressure ratio, design drop pressure ratio and geometric deflection vector angle is proposed. The results show that the maximum error of thrust coefficient is 0.41%, that of discharge coefficient is 1.58%, and that of vector angle is 1.76. The mathematical model proposed in this paper has strong generality while maintaining the engineering significance in complex systems.