Comparative Study on the Computation Performance Between the Dynamic-Mesh Framework and Non-inertial-Coordinate Framework for Solving Heat and Mass Transfer Problems

Flow and heat transfer is an important problem that must be considered in the design and operation management of various kinds of energy systems and equipment. Sometimes, these systems or equipment are subjected to body motion like rolling motion, making the heat and mass transfer characteristic more complexed. Numerical methods are the most powerful methods for clarification of such complex heat and mass transfer problems. The numerical modelling for heat and mass transfer problems can be performed by two frame works, the dynamic-mesh framework and the non-inertial-coordinate framework. The computational performances of these two frameworks are important reference for choosing the numerical modelling method. In this paper, these two frameworks are comparatively investigated in term of the grid independence, timestep independence, and convergence, with single-phase and two-phase convection flows in a square cavity subjected to rolling motions. The research results show that the computaion in non-inertial-coorndinate framework achives grid-indepence and timestep-indepence more easily for two-phase flow problems than that in dynamic-mesh framework; however, theses two frameworks behave similary for single-phase problems. In terms of convergence, although the non-inertial-coordinate framework requires more iterations than dynamic-mesh framework for the same mesh, however it can be more efficient since less grid cells and larger timestep are acceptable for reaching the grid-indepence and timestep-indepence results.