氩气和水蒸气膨胀中均匀凝结的非平衡数值模型。

Nonequilibrium numerical model of homogeneous condensation in argon and water vapor expansions.

机构信息

University of Southern California, Los Angeles, California 90089, USA.

出版信息

J Chem Phys. 2010 Jun 28;132(24):244105. doi: 10.1063/1.3447379.

PMID:20590179

Abstract

A computational approach capable of modeling homogeneous condensation in nonequilibrium environments is presented. The approach is based on the direct simulation Monte Carlo (DSMC) method, extended as appropriate to include the most important processes of cluster nucleation and evolution at the microscopic level. The approach uses a recombination-reaction energy-dependent mechanism of the DSMC method for the characterization of dimer formation, and the RRK model for the cluster evaporation. Three-step testing and validation of the model is conducted by (i) comparison of clusterization rates in an equilibrium heat bath with theoretical predictions for argon and water vapor and adjustment of the model parameters, (ii) comparison of the nonequilibrium argon cluster size distributions with experimental data, and (iii) comparison of the nonequilibrium water cluster size distributions with experimental measurements. Reasonable agreement was observed for all three parts of the validation.

摘要

提出了一种能够在非平衡环境中模拟均匀凝结的计算方法。该方法基于直接模拟蒙特卡罗（DSMC）方法，并进行了适当扩展，以包括在微观水平上的团簇成核和演化的最重要过程。该方法使用 DSMC 方法的重组-反应能量相关机制来描述二聚体的形成，并使用 RRK 模型来描述团簇的蒸发。通过（i）在平衡热浴中与氩气和水蒸气的理论预测进行比较，并调整模型参数，对模型进行了三步测试和验证；（ii）与实验数据进行非平衡氩气团簇尺寸分布的比较；（iii）与实验测量进行非平衡水团簇尺寸分布的比较。在验证的所有三个部分都观察到了合理的一致性。