화학공학소재연구정보센터
AIChE Journal, Vol.63, No.7, 3158-3176, 2017
Arbitrary shaped ice particle melting under the influence of natural convection
This work is devoted to numerical simulations of an arbitrary shaped ice particle melting inside water under the influence of natural convection. Specifically, four different shapes of the ice particle have been studied: sphere, cylinder, cross shaped cylinder, and irregular sphere with radial bumps on its surface. A 2D axisymmetric particle-resolved numerical model has been employed on a fixed grid to study the detailed melting dynamics of an ice particle. The solid-liquid interface is treated as a porous medium characterized by the permeability coefficient which is used to damp the velocity values inside the interface. The model results have been compared with an existing experimental results produced by A. Shukla et al. (Metal Mater Trans B. 2011; 42(1):224-235). Very good agreement between our predictions and experimental data have been achieved. Based on the analysis of numerical simulation results, melting process is found to advance through two distinct regimes, namely, establishment of the natural convection and active melting of ice particle exhibiting substantial amount of fluid-particle interactions. A set of dimensionless parameters have been identified to distinguish between regimes. Finally, we developed a semi-empirical to predict the melting of any arbitrary shaped ice particle and validated it against the particle-resolved numerical simulation and experimental results. The comparison showed good agreement. Finally, the presented semi-empirical model can be used as sub-grid model in Euler-Lagrange based numerical models to study the phase change phenomena in particulate flow systems. (c) 2017 American Institute of Chemical Engineers AIChE J, 63: 3158-3176, 2017