0
MICRO/NANOSCALE HEAT TRANSFER—PART II

Molecular Dynamics Based Analysis of Nucleation and Surface Energy of Droplets in Supersaturated Vapors of Methane and Ethane

[+] Author and Article Information
Jadran Vrabec1

Thermodynamik und Energietechnik, Universität Paderborn, Warburger Str. 100, 33098 Paderborn, Germanyjadran.vrabec@upb.de

Martin Horsch

Thermodynamik und Energietechnik, Universität Paderborn, Warburger Str. 100, 33098 Paderborn, Germany

Hans Hasse

Lehrstuhl für Thermodynamik, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 44, 67663 Kaiserslautern, Germany

1

Corresponding author.

J. Heat Transfer 131(4), 043202 (Feb 11, 2009) (4 pages) doi:10.1115/1.3072909 History: Received March 31, 2008; Revised August 05, 2008; Published February 11, 2009

Homogeneous nucleation processes are characterized by the nucleation rate and the critical droplet size. Molecular dynamics simulation is applied for studying homogeneous nucleation during condensation of supersaturated vapors of methane and ethane. The results are compared with the classical nucleation theory (CNT) and the Laaksonen–Ford–Kulmala (LFK) model that introduces the size dependence of the specific surface energy. It is shown for the nucleation rate that the Yasuoka–Matsumoto method and the mean first passage time method lead to considerably differing results. Even more significant deviations are found between two other approaches to the critical droplet size, based on the maximum of the Gibbs free energy of droplet formation (Yasuoka–Matsumoto) and the supersaturation dependence of the nucleation rate (nucleation theorem). CNT is found to agree reasonably well with the simulation results, whereas LFK leads to large deviations at high temperatures.

FIGURES IN THIS ARTICLE
<>
Copyright © 2009 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 5

Nucleation rates of methane and ethane at high temperatures (0.89 and 0.92 Tc) from simulation (17) according to the Yasuoka–Matsumoto method with different threshold sizes (◼) as well as CNT (—) and LFK (- - -)

Grahic Jump Location
Figure 6

Critical droplet size for methane and ethane from maxima of the Gibbs free energy of droplet formation (◼) and the supersaturation dependence of the nucleation rate (○) as well as CNT (—) and LFK (- - -)

Grahic Jump Location
Figure 1

Dependence of the LFK surface energy coefficient κ(ι) for methane (—) and ethane (- - -) on the droplet size ι

Grahic Jump Location
Figure 2

Number of droplets containing at least 25, 100, …, 1000 molecules over simulation time (17). Methane was regarded at 130 K and 1.606 mol/l in a volume of (63.7 nm)3.

Grahic Jump Location
Figure 3

Dependence of the Gibbs free energy of droplet formation on the droplet size for ethane at 280 K and two different densities, calculated from the metastable equilibrium (◼) and the steady state distribution (○) as well as CNT (—) and LFK (- - -)

Grahic Jump Location
Figure 4

Nucleation rates of methane and ethane at low temperatures from simulation (17) determined according to the Yasuoka–Matsumoto method with different threshold sizes (◼) as well as CNT (—) and LFK (- - -)

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In