首页|基于ReaxFF-MD的有限催化模型数值模拟

基于ReaxFF-MD的有限催化模型数值模拟

Numerical Simulation of Finite-Rate Catalytic Model Based on ReaxFF-MD

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目前,CFD方法预测表面热流时,一般假设壁面条件为完全催化壁或完全非催化壁.不同壁面催化条件会极大影响热流预测结果,采用有限催化模型能够得到较为合理的数值解.然而,高焓化学反应流在材料表面发生催化复合的过程具有非线性、非平衡、多尺度等特征,使得准确描述有限催化模型极其困难.基于微观尺度的理论和模拟计算,采用反应分子动力学方法构建了一种描述O和N原子与SiO2 表面相互作用的有限催化模型,计算对比了不同催化条件下航天飞机轨道器的再入飞行流场.结果表明有限催化模型的热流预测值与STS-3 海拔 70.1~57.8 km范围内的飞行试验数据吻合良好,模型具有一定程度的准确性.
At present,when CFD method is used to predict surface heat flux,it is generally assumed that the wall condition is full-catalytic wall or non-catalytic wall.Heat flux prediction can be greatly affected by different wall catalytic conditions,and a more reasonable numerical solution can be obtained by using finite-rate catalytic model.However,due to the nonlinear,nonequilibrium,and multiscale characteristics of the catalytic recombination process of high-enthalpy chemical reaction flows on material surfaces,it is extremely difficult to accurately describe the finite-rate catalytic model.In this paper,a finite-rate catalytic model describing the interaction of O and N atoms with SiO2 surface was constructed by ReaxFF-molecular dynamics method based on the theory and simulation at the microscale.The reentry flow fields of space shuttle orbiter under different catalytic conditions were calculated and compared.The results show that the predicted heat flux of the finite-rate catalytic model agrees well with the flight test data of STS-3 in the altitude range of 70.1 km to 57.8 km,and the model has a certain degree of accuracy.

hypersonicchemical nonequilibriumfinite-rate catalysisReaxFF-MD

宋嘉豪、莫凡、高振勋

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广东空天科技研究院(南沙),广东 广州 511458

北京航空航天大学航空科学与工程学院,北京 100191

高超声速 化学非平衡 有限催化 反应分子动力学

2024

气体物理

气体物理

CSTPCD
ISSN:
年,卷(期):2024.9(6)