一种稀薄两相流动的数值模拟方法

A numerical method for simulating rarefied two phase flow

从描述粒子运动的微观层次出发,采用双向耦合技术,建立了一种适用于稀薄条件下两相流动的DSMC数值模拟方法。对相间相互作用进行解耦处理,实现了气固两相间动量和能量相互作用的模拟。相关算例验证了方法的可靠性。结果表明:在大样本统计平均条件下,该模拟方法能够保证相间动量和能量交换时守恒,固体颗粒尺寸、气体稀薄程度等条件对相间的相互作用有很大的影响。

A numerical simulation approach is presented to simulate rarefied two phase flow by applying two-way coupling technical in DSMC method. The interaction between rarefied gas and solid particles is dealt with decoupled approximation to compute momentum and energy ex- change between phases. Results of simulation examples validate the methods and the models by the comparison of the present results with that of typical confirmed results from references, and indicate that it can ensure momentum and energy conservation between phases even in case of large sample number. A two-phase plume flow field from solid rocket engine is simulated using this present method. Away from the engine nozzle, gas and solid particles have a greater impact caused by temperature drop and increases of the speed of particles. The particles temperature away from the nozzle exit tends to be balanced. Simulation shows that the particle size and gas rarefaction would affect the interaction evidently.