Molecular dynamics simulation of thermal accommodation coefficients for laser-induced incandescence sizing of nickel particles |
| |
Authors: | K J Daun J T Titantah and M Karttunen |
| |
Institution: | (1) Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue W., Waterloo, ON, Canada, N2L 3G1;(2) Department of Applied Mathematics, University of Western Ontario, 1151 Richmond St. N., London, ON, Canada, N6A 5B;(3) Department of Chemistry, University of Waterloo, 200 University Ave. W., Waterloo, ON, Canada, N2L 3G1 |
| |
Abstract: | Extending time-resolved laser-induced incandescence (TiRe-LII), a diagnostic traditionally used to characterize soot and other
carbonaceous particles, into a tool for measuring metal nanoparticles requires knowledge of the thermal accommodation coefficient
for those systems. This parameter can be calculated using molecular dynamics (MD) simulations provided the interatomic potential
is known between the gas molecule and surface atoms, but this is not often the case for many gas/surface combinations. In
this instance, researchers often resort to the Lorentz–Berthelot combination rules to estimate the gas/surface potential using
parameters derived for homogeneous systems. This paper compares this methodology with a more accurate approach based on ab
initio derived potentials to estimate the thermal accommodation coefficient for laser-energized nickel nanoparticles in argon.
Results show that the Lorentz–Berthelot combining rules overestimate the true potential well depth by an order of magnitude,
resulting in perfect thermal accommodation, whereas the more accurate ab initio derived potential predicts an accommodation
coefficient in excellent agreement with experimentally-determined values for other metal nanoparticle aerosols. This result
highlights the importance of accurately characterizing the gas/surface potential when using MD to estimate thermal accommodation
coefficients for TiRe-LII. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|