大型分段装药发动机绝热环烧蚀特性实验研究

Experimental Investigation on Ablation Characteristic of Restrictor Plate in Large Segment-Propellant Rocket Motor

为了研究大型分段装药发动机绝热环限燃层的烧蚀规律和特性,针对典型发动机开展了不同时刻和限燃层高度条件下三维两相流场的数值模拟,进行了限燃层表面烧蚀环境的特征分析和烧蚀状态参数提取,设计并研制了地面模拟烧蚀实验装置,开展了不同颗粒冲刷状态条件对限燃层烧蚀影响规律的实验研究,并采用扫描电镜分析了限燃层迎风面和背壁面炭化层的微观形貌。研究结果表明:(1)大型分段装药发动机流道中不同位置处绝热环限燃层表面的两相流冲刷状态不同,由于绝热环在流道中的阻碍作用,其表面形成了一种颗粒聚集浓度较低、冲刷速度较高而气相速度较低的烧蚀环境;(2)地面模拟实验结果表明绝热环限燃层的炭化烧蚀率随颗粒冲刷速度增加而增加,且增加幅度逐渐变大;(3)实验后限燃层的核心冲刷区域表面无炭化层残留,其烧蚀模式由机械剥蚀破坏效应主导。

Three-dimensional two-phase flow in typical large segment-propellant rocket motor with different height of restrictor at different time was simulated to investigate the ablation rules and characteristics of restrictor plate.The ablation circumstance on the restrictor surface was analyzed and the ablation state parameters were extracted.The ground experimental device of ablation simulation was designed and the ablation experiments with different particle erosion states were carried out.The ablation rules of restrictor with the change of particle state were obtained.Combined with the electronic microscope scanning results of the charred layer of restrictor at windward side and back wall,the ablation characteristics and patterns of restrictor material at different experimental conditions were analyzed.The results show that:(1) The twophase flow erosion state near the restrictor plate surface at different position in segment-propellant rocket motor is varied.Because of the blocking effect of the restrictor,the ablation circumstance with low particle concentration density,high erosion velocity of particle phase and low flow velocity of gas phase are formed near the restrictor surface.(2) The ground experiments show that the charred layer ablation rate of restrictor increases with the increment of particle erosion velocity,and the amplitude of increment is gradually enlarged.(3) There is no residuals of charred layer in the erosion surface after the experiments,and the main ablation pattern is particle mechanical erosion.