超声速固体粒子侵蚀的欧拉模型

Eulerian Model of Solid Particle Erosion at Hypersonic Speed

利用计算流体力学(CFD)技术,引入粒子容积分数的概念,基于欧拉两相流模型,计算超声速飞行器侵蚀表面粒子速度和容积分数分布,模拟侵蚀后的三维表面外形。以超声速计算结果为基础,针对现有拉格朗日法计算侵蚀后退率的局限性,推导出适用于欧拉模型的计算公式。采用本文的数值模拟方法,模拟侵蚀后飞行器的外形,并与实验结果进行对比,验证了本文方法的正确性。计算和分析了不同环境参数对侵蚀量的影响,结果表明,马赫数和粒子容积分数对侵蚀量有较大影响,而粒子容积分数不变的情况下,粒子直径对侵蚀量影响不大。

In order to simulate vehicle erosion under hypersonic conditions, the method of computational fluid dynamics （CFD） technique is used. Based on Eulerian two phase flow model, the concept of particle volume fraction is set up and the equations of solid particles distribution are derived. Hypersonic flow fields and distribution of particle volume fraction are calculated as the basis of numerical simulation. The erosion calculation formula based on the Lagrange method has its limitations ; therefore, a new formula of erosion amount suitable for Eulerian model is derived. The erosion amount of model is simulated by using the above mentioned computational method, and the calculated results are compared with experimental results in order to verify the validity of the method. The effects of environment parameters on the erosion are studied. The calculated results show that Mach number and particle volume fraction have great influence on the erosion amount, and particle diameter has almost no effect on the erosion amount when particle volume fraction remains unchanged.