双脉冲发动机Ⅰ脉冲工作过程中EPDM隔层烧蚀特性

Ablation characteristics of EPDM separation device of dual-pulse motor during the pulseⅠoperation

针对双脉冲发动机脉冲隔离装置——三元乙丙(EPDM)隔层的烧蚀问题,建立了Ⅰ脉冲发动机燃烧室两相流动仿真模型,分析了隔层的热载荷环境特性,开展了隔层动态烧蚀过程仿真研究,获得了隔层温度和烧蚀量的变化历程,并通过隔层烧蚀实验进行了验证。研究结果表明,Ⅰ脉冲工作初期隔层外表面温度急剧增加,烧蚀量缓慢增加,随着热流的持续作用,隔层内部温度上升速率变缓,而隔层烧蚀量急剧增加。隔层烧蚀较为严重的区域为轴向与径向的过渡段,这与隔层表面热流密度的分布趋势一致。计算得到隔层环向削弱槽附近烧蚀厚度为2.0 mm,实验测得隔层烧蚀厚度为2.21 mm,误差为9.5%,表明隔层烧蚀计算模型具有足够的精度。

Aiming at the ablation problem of the pulse separation device for dual-pulse motor,the two-phase flow simulation model of the motor chamber was established,and the thermal load environment characteristics of the separation device were ana-lyzed.The ablation process of the separation device was simulated,and the variation history of ablation amount and temperature for separation device was obtained,which was verified by the ablation test.The results show that at the initial stage of pulse I operation,the outer surface temperature of the separation device increases sharply,but the ablation amount increases slowly.With the continu-ous effect of heat flux,the temperature inside the separation device increases slowly,but the ablation amount increases sharply.Se-vere ablation occur in the axial and radial transition section,which is consistent with the heat flux density distribution.The ablation thickness of the separation device near the circumferential weakening groove is 2.0 mm by calculation,and the ablation thickness of the separation device measured by experiment is 2.21 mm,so an error of 9.5%indicate that the accuracy of the ablation calculation model is sufficient.