Kinetic nucleation model for free expanding water condensation plume simulations

Zheng Li, Jiaqiang Zhong, Deborah A. Levin, Barbara J. Garrison

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


Recent direct simulation Monte Carlo (DSMC) simulations of homogeneous condensation in free expansion water plumes [Z. Li, J. Zhong, D. A. Levin, and B. Garrison, AIAA J. 47, 1241 (2009)] show that the nucleation rate is a key factor for accurately modeling condensation phenomenon. In this work, we use molecular dynamics (MD) simulations of a free expansion to explore the microscopic mechanisms of water dimer formation and develop collision models required by DSMC. Bimolecular and termolecular dimer cluster formation mechanisms are considered and the former is found to be the main mechanism in expanding flows to vacuum. MD simulations between two water molecules using the simple point charge intermolecular potential were performed to predict the bimolecular dimer formation probability and the probability was found to decrease with collision energy. The formation probabilities and postcollisional velocity and energy distributions were then integrated into DSMC simulations of a free expansion of an orifice condensation plume with different chamber stagnation temperatures and pressures. The dimer mole fraction was found to increase with distance from the orifice and become constant after a distance of about two orifice diameters. Similar to experiment, the terminal dimer mole fraction was found to decrease with chamber stagnation temperatures and increase linearly with chamber stagnation pressures which is consistent with a bimolecular nucleation mechanism.

Original languageEnglish (US)
Article number174309
JournalJournal of Chemical Physics
Issue number17
StatePublished - 2009

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy
  • Physical and Theoretical Chemistry


Dive into the research topics of 'Kinetic nucleation model for free expanding water condensation plume simulations'. Together they form a unique fingerprint.

Cite this