固体发动机内弹道计算不确定性研究

Research on internal ballistics calculation uncertainty of solid rocket motors

建立了固体发动机一维混合内弹道计算模型,提出了提高内弹道预估精度的工程方法。采用系统辨识法建立燃速模型、计算药柱初温分布和预估药柱真实燃面,建立了内弹道性能散布分析方法。算例应用研究表明,燃速模型参数不确定性是影响发动机内弹道计算精度的主要因素,除燃速模型参数外,对总冲变化的显著影响因子依次是燃气比热容比、推力系数因子、特征速度因子和药柱密度,对工作时间变化的显著影响因子依次是特征速度因子、药柱初温和药柱密度。

The model of 1-D hybrid internal ballistics calculation was established, in order to improve the prediction accuracy of internal ballistics. The burning rate model was set up by using system identification method to calculate the initial temperature distribution, predict the true burning area of grain and establish the analysis method of internal ballistics performance distribution. The results show that burning rate model parameter uncertainty is the key factor which influences the prediction accuracy of internal ballistics. Besides burning rate model parameters, the prominent influence factors on total impulse are specific heat ratio, thrust coefficient factor, characteristic velocity factor and grain density sequentially, while those on operation time are characteristic velocity factor, grain initial temperature and grain density sequentially.