颗粒冲刷条件下绝热层二维烧蚀计算

Two-dimensional ablation calculation of insulation eroded by particles

在颗粒冲刷条件下绝热层烧蚀试验研究的基础上,对该条件下的绝热层烧蚀机理进行了理论分析,建立了颗粒冲刷条件下的绝热层二维炭化烧蚀模型,进行了该条件下的绝热层烧蚀计算。烧蚀机理分析认为,冲刷条件下绝热层烧蚀加剧的直接原因为颗粒对炭化层的机械剥蚀作用,经回归分析得到了炭化层厚度Ht和颗粒浓度Gp、颗粒冲刷速度vp、颗粒冲刷角度α之间的经验关系式:Ht=5.761G-p0.013 7(vpsinα)-0.409。烧蚀计算模型基于二维适体网格,并发展了一种自适应加密和加强网格正交化的方法。计算获得的绝热层型面推移结果和利用X射线实时荧屏分析(RTR)测量得到的绝热层动态烧蚀试验结果吻合较好,表征出了颗粒冲刷条件下绝热层烧蚀过程的型面变化规律。该烧蚀模型适用于颗粒冲刷条件下绝热层的烧蚀计算。

Based on the ablation test of insulation eroded by particles, ablation mechanism of insulation was analyzed, and a two-dimensional charring ablation model was established ,furthermore ablation calculation was carried out. Ablation mechanism analysis results show that the direct reason why insulation eroded by particles presents severe ablation is mechanical erosion of particles on carbonization layer. By regression analysis ,the experience relationship between charred layer thickness H, ,particle concentration Gp ,particle eroding velocity Vp ,particle eroding angle α was obtained：Ht=5.761Gp^-0.013 7（vpsinα）^-0.409 The ablation model wasbased on two-dimensional body-fitted mesh,and a method for self-adaptive refined and reinforced orthogonal mesh was developed. The calculation results of regression rate of insulation surface were consistent with dynamic test data measured by X-ray real-time screen method. Contour change law of insulation eroded by particles during the erosion process was characterized. The ablation model is applicable to erosion calculation of insulation eroded by particles.