Study On The Design Technology Of Small Solid Motor Swing Nozzle

This thesis aimed at contrastive analysis and test verification of the small swing nozzle of solid rocket motor.It started with a brief introduction of the small solid rocket motor nozzle used abroad in the spacecraft,and then researched the technology of small swing nozzle both here and abroad.After the analysis and comparison of the advantages and disadvantages of some present common different swing nozzles, the rolling ball swing nozzle was finally chosen as the main study object of this thesis for its technical superiority.It studied the design method of small swing nozzle, and presented a space vector layout based anti-torque device to meet the anti-torque technical requirement of rolling ball socket swing nozzle.It also studied the analytic method of the contact stress between the rolling ball and the socket structure of the rolling ball swing nozzle, and compared with the swing nozzle experimental data. It was verified that the contact stress analytic method can meet the engineering design requirements.In consideration of the influence on the thermal structure, erosion and performance of the nozzle after the nozzle attaining certain swing angle, the flow field simulation analysis software was applied to simulate the heat flow field with high temperature, high pressure and high speed after the nozzle swung. The grain scour in the empty connection cavity of the nozzle inlet, throat erosion and thrust performance were predicted,and the predicted results tallied with the nozzle ground ignition test results.Through ground cold swing test and ground ignition test, the structure reliability, the performance stability and the nozzle swinging reliability of this thesis design method based rolling ball socket swing nozzle was assessed. It was verified that the swing nozzle met the design technical requirements,and the effectiveness of the design method was proven. This thesis study provided useful reference for the development of swing nozzle technology.