Title Vandens garavimo/kondensacijos procesų tyrimas molekulinės dinamikos metodu /
Translation of Title Molecular Dynamics Investigation of Water Evaporation/Condensation Processes.
Authors Skarbalius, Gediminas
Full Text Download
Pages 65
Keywords [eng] molecular dynamics simulation ; water ; liquid-vapour equilibria, interphase thickness ; velocity distribution ; condensation coefficient
Abstract [eng] In present master’s thesis, molecular dynamics simulations of water liquid-vapour phase equilibria were carried out in order to investigate the effect of molecular flexibility on phase change boundary conditions. The obtained results show that the one over the “10-90” interphase thickness is decreasing linear function of liquid temperature in simulated temperature range for TIP3P, SPC/E and flex-FPC molecular models. The condensation coefficient obtained with flex-FPC molecular model is a function of liquid phase temperature and surface-normal component of translational motion energy of impinging vapour molecule. Furthermore, the condensation coefficients obtained in present master’s thesis using flexible molecular model were considerably higher than condensation coefficients obtained with rigid SPC/E molecular model. No dependency of condensation coefficient on surface-tangential components of translational motion energy and rotational energy were observed. The energetic analysis of reflecting molecules showed that changes of surface-normal and surface-tangential components of translational energy and the rotational energy of reflected molecules are proportional to respective energy components of impinging molecules. Finally, the velocity distribution functions of evaporating, condensing and reflecting molecules in surface-tangential directions agree with the Maxwellian distribution at 503 K. However, the mean value of surface-normal component of translational velocity of evaporating molecules is slightly higher than mean velocity obtained from Maxwellian distribution at 503 K temperature and the velocity distribution of reflecting molecules is shifted to lower velocity side.
Dissertation Institution Kauno technologijos universitetas.
Type Master thesis
Language English
Publication date 2019