Simulating rotationally inelastic collisions using a direct simulation Monte Carlo method
Simulating rotationally inelastic collisions using a direct simulation Monte Carlo method
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使用直接模拟蒙特卡罗方法模拟旋转非弹性碰撞
DOI：
10.1080/00268976.2015.1098740
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发表时间：
2015
影响因子：
1.7
通讯作者：
T. Softley
中科院分区：
文献类型：
--
作者：
O. Schullian;J. Loreau;N. Vaeck;A. Avoird;B. R. Heazlewood;C. J. Rennick;T. Softley
本文介绍了一种用直接模拟蒙特卡罗（DSMC）方法模拟旋转冷却的新方法，并将其应用于氦气超音速射流中氨的旋转冷却。该方法利用从头计算的转动态变化截面作为碰撞能量的函数计算。DSMC模拟中的每个粒子都标记有随时间演化的旋转种群矢量。转化为平移的能量转移是根据在指定碰撞能量下该群体的平均能量转移计算的。模拟进行了比较与连续模型的轴上的密度，温度和速度;旋转温度作为从喷嘴的距离的函数是在雅阁与预期的实验测量。该方法可以应用于其他类型的气体混合动力学在非均匀条件下，如缓冲气体冷却的NH3的He。
A new approach to simulating rotational cooling using a direct simulation Monte Carlo (DSMC) method is described and applied to the rotational cooling of ammonia seeded into a helium supersonic jet. The method makes use of ab initio rotational state changing cross sections calculated as a function of collision energy. Each particle in the DSMC simulations is labelled with a vector of rotational populations that evolves with time. Transfer of energy into translation is calculated from the mean energy transfer for this population at the specified collision energy. The simulations are compared with a continuum model for the on-axis density, temperature and velocity; rotational temperature as a function of distance from the nozzle is in accord with expectations from experimental measurements. The method could be applied to other types of gas mixture dynamics under non-uniform conditions, such as buffer gas cooling of NH3 by He.