针栓喷注器中心推进剂偏转角模型分析研究

Central Propellant Deflection Angle Model of Pintle Injector

关键词:  液体火箭发动机  喷注器  推进剂  流场  变推力  数值仿真

Key words:  Liquid rocket engine  Injector  Propellant  Flow field  Variable thrust  Numerical simulation

摘要:

为了实现针栓喷注器中心推进剂偏转角的准确预测，基于流场分析建立了中心推进剂偏转角理论模型。从动量守恒方程推导了中心推进剂偏转角公式，通过数值仿真和试验结果对其进行验证，并分析了工况参数和结构参数对中心推进剂偏转角的影响规律。结果表明：理论模型预测值与数值仿真和试验结果很好地吻合，套筒遮挡喷注面积对偏转角影响最大，在变推力时偏转角随着套筒遮挡喷注面积增加而减小。喷注压降、中心筒壁厚和底部凹腔深度对中心偏转角影响很小，当套筒遮挡喷注面积一定时，中心筒底部有凹腔的偏转角比没有凹腔的偏转角约大6°，该模型为针栓喷注器工程设计和进一步精确计算变推力下的雾化角提供了重要参考。

Abstract:

In order to accurately predict the central propellant deflection angle of pintle injector， the theoretical model of central propellant deflection angle was established based on flow field analysis. A central propellant deflection angle formula was deduced from the momentum conservation equation， which was verified by numerical simulation and experimental results. Moreover， the effects of structure parameters and working parameters on the central propellant deflection angle were analyzed. The results show that the predicted values of the theoretical model are in good agreement with the numerical and experimental results. The injection area of sleeve shielding has the greatest influence on the deflection angle of the central propellant. In the case of variable thrust， the central deflection angle decreases as the injection area of sleeve shielding increases. Injection pressure drop， wall thickness and cavity depth at the bottom of central cylinder have little effect on central deflection angle. When the injection area of sleeve shielding is constant， the deflection angle with a cavity at bottom of the central cylinder is about 6° larger than that without a cavity. This model can provide an important reference for the engineering design and the further accurate calculation of spray angle at variable thrust of pintle injector.