凝并与沉降共存的直接蒙特卡罗模拟及其验证

Direct simulation Monte Carlo(DSMC) and validation for aerosol undergoing simultaneous coagulation and settling

气溶胶动力学方程是描述气溶胶动力学变化的主要方程,凝并与沉降共存问题是相关领域的常见的问题。建立了对该类问题的分段算法和直接蒙特卡罗模拟(Direct Simulation Monte Carlo method,DSMC)计算方法,对DSMC中事件后系统参数的更新方法进行了改进,并提出了用纳入解析解的分段算法的结果对DSMC模拟结果进行验证的方法。结果表明,改进的DSMC算法显著提高了计算效率,模拟结果与其它算法的结果一致。

The Direct Simulation Monte Carlo method （DSMC） is one of the popular numerical simulation methods for solving the General Dynamic Equation （GDE）, a description of aerosol dynamics. Coagulation and Settling are usually the most important mechanisms in the GDE. A modified DSMC for simulation of simultaneous coagulation and settling is proposed to save the computation time. Its evaluation method based on the sectional method and self-preserved distribution is proposed in this paper. The results of simulations show that the time consumption of the DSMC method could be reduced by a factor of 100 and 1000 while running 1000 and 10000 particles respectively. And the results of the DSMC method are consistent with those of the sectional method.