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基于一种颗粒冲刷状态参数大范围可调的高过载地面模拟试验发动机,针对三元乙丙(EPDM)绝热材料开展了15次烧蚀实验,获得了颗粒冲刷状态参数和炭化烧蚀率之间的宏观影响规律,通过扫描电镜分析了炭化层结构的形貌特征,并以炭化层孔隙结构为纽带,剖析了颗粒冲刷条件下热化学烧蚀和颗粒侵蚀之间的耦合关系。结果表明:(1)存在一个临界速度,当冲刷速度低于临界速度时,颗粒浓度、速度和角度对炭化烧蚀率影响较小,而当冲刷速度高于临界速度时,炭化烧蚀率随速度的增加而急剧增加,角度影响也较大;(2)不同的颗粒冲刷状态条件下,炭化层形貌结构差异较大,内部存在明显的“致密/疏松”结构;(3)根据颗粒冲刷参数和炭化层形貌关系,提出了3种典型的烧蚀冲刷状态,即弱冲刷状态、颗粒沉积状态及强冲刷状态;(4)分析了不同颗粒冲刷状态下的绝热层烧蚀过程,获得了热化学烧蚀和颗粒侵蚀之间的耦合关系。
Based on a large overburden ground simulation test engine with a large range of particle flushing parameters, a total of 15 ablation experiments were carried out on EPDM insulation to obtain the relationship between particle erosion parameters and carbonization ablation rate The morphology of the carbonized layer was analyzed by scanning electron microscopy. The relationship between thermal ablation and particle erosion was analyzed by using the pore structure of carbonized layer as the bond. The results show that: (1) there is a critical velocity. When the scouring velocity is lower than the critical velocity, the effect of particle concentration, velocity and angle on the carbonization ablation rate is small. When the scouring velocity is higher than the critical velocity, the ablation rate (2) Under different conditions of particle erosion, the topography structure of carbonized layer is quite different, and there is obvious “dense / loose” structure inside; (3) According to Three kinds of typical ablation scouring states, namely weak scouring state, particle deposition state and strong scouring state, were put forward. (4) The ablation process of insulation layer under different particle scouring conditions , The coupling between thermochemical ablation and particle erosion was obtained.