Lattice Boltzmann simulation of melting of a phase change material confined within a cylindrical annulus with a conductive inner wall using a body-fitted non-uniform mesh
Publication date: Available online 13 October 2018
Source: International Journal of Thermal Sciences
Author(s): Gholamreza Imani
In this paper, the lattice Boltzmann method on a body-fitted non-uniform mesh is employed to simulate the outward melting of a pure phase change material (PCM) confined in a cylindrical annulus with a conducting inner wall, for and . To perform the propagation step on the non-uniform mesh, the Taylor series least square method is used. After verification of the developed code against the experimental and numerical benchmark solutions, the effects of Reynolds number, radius ratio , wall to PCM conductivity ratio , dimensionless inner wall thickness , and thermal boundary condition on the melting process are studied. It is concluded that the smaller radius ratios enhance the melting process. It is seen that the results of cases with and are in good agreement with each other and with the corresponding cases where the wall thickness is ignored. However, this is not the case for . Moreover, it is seen that for and , the bigger enhances the melting process whereas, for , the reverse is true. Finally, it is figured out that the effect of applying the adiabatic conditions on the outer cylinder, instead of the constant temperature, enhances the liquid fraction in such a way that this improvement is seen to be more pronounced for the times after the melted PCM first touches the outer cylinder.