Multiparameter Optimization of Thrust Vector Control with Transverse Injection of a Supersonic Underexpanded Gas Jet into a Convergent Divergent Nozzle

Vladislav Emelyanov,Mikhail Yakovchuk,Konstantin Volkov

doi:10.3390/en14144359

Abstract

The optimal design of the thrust vector control system of solid rocket motors (SRMs) is discussed. The injection of a supersonic underexpanded gas jet into the diverging part of the rocket engine nozzle is considered, and multiparameter optimization of the geometric shape of the injection nozzle and the parameters of jet injection into a supersonic flow is developed. The turbulent flow of viscous compressible gas in the main nozzle and injection system is simulated with the Reynolds-averaged Navier–Stokes (RANS) equations and shear stress transport (SST) turbulence model. An optimization procedure with the automatic generation of a block-structured mesh and conjugate gradient method is applied to find the optimal parameters of the problem of interest. Optimization parameters include the pressure ratio of the injected jet, the angle of inclination of the injection nozzle to the axis of the main nozzle, the distance of the injection nozzle from the throat of the main nozzle and the shape of the outlet section of the injection nozzle. The location of injection nozzle varies from 0.1 to 0.9 with respect to the length of the supersonic part of the nozzle; the angle of injection varies from 30 to 160 degrees; and the shape of the outlet section of the injection nozzle is an ellipse with an aspect ratio that varies from 0.1 to 1. The computed fluid flow in the combustion chamber is compared with experimental and computational results. The dependence of the thrust as a function of the injection parameters is obtained, and conclusions are made about the effects of the input parameters of the problem on the thrust coefficient.

Highlights

To control the movement of aircraft in accordance with the required trajectory, it is necessary to be able to change the magnitude and direction of the velocity vector in flight, as well as the orientation of the aircraft axes in space
The influence of the parameters of the problem, such as the pressure ratio of the injected jet, the angle of inclination of the injection nozzle to the axis of the main nozzle, the distance of the injection nozzle from the critical section of the main nozzle and the shape of the outlet section of the injection nozzle, on the coefficient of the amplification of the nozzle thrust is discussed
L j is the relative distance from the critical section of the main nozzle to the outlet of the injection nozzle, α j is the angle of inclination of the injection nozzle to the axis of the main nozzle, d1 and d2 are the length of the small and the major axes of the ellipse forming the outlet section of the injection nozzle and A∗ and A a are the areas of the critical and outlet sections of the injection nozzle

Summary

Introduction

To control the movement of aircraft in accordance with the required trajectory, it is necessary to be able to change the magnitude and direction of the velocity vector in flight, as well as the orientation of the aircraft axes in space. Thrust vector control with the injection of the gas jet into a nozzle is relatively simple without the need for high-temperature sealing due to the structural decoupling of the SRM nozzle from the TVC system, reducing the thermal loading [1,2]. To create a control force in rocket engines, gas injection into the supersonic part of the nozzle is used [3,4]. The generated control force consists of two components, the thrust of the injection nozzle and the force applied to the walls of the main nozzle and arising from the redistribution of the pressure in the region of the interaction of the flows [5]. The magnitude of the control force depends on the location of the injection hole, the injection angle and the pressure ratio of the injection nozzle.

Methods

Results

Conclusion