The enthalpy-based lattice Boltzmann method (LBM) for simulation of NePCM melting in inclined elliptical annulus

Abstract

Constrained melting of ice as a PCM11Phase Change Material. in inclined elliptical annulus should be studied. Efficiency of heat transfer enhancement methods such as insertion of Cu nanoparticles and metallic porous matrix in this heat storage system must be determined. Porous material is made of alloys of Nickel and Steel. The enthalpy-based LBM22Lattice Boltzmann Method. with a D2Q9-DDF33Double Distribution Function. model at the REV44Representative Elementary Volume. scale is implemented. There is thermal equilibrium condition between porous media and PCM. Also, for NEPCM55Nanoparticles-Enhanced PCM. melting, the single phase flow model is adopted. Particle diameter in nanofluid is equal to 100 nm. The sub-cooling of solid PCM is ignored. Prandtl number, Stefan number, Rayleigh number and Darcy number are 6.2, 1, 2×105 and 10−3, respectively. The volumetric concentric of the nanoparticles is between 0 and 0.02. Porosity is between 1 and 0.9. It is found that inclination of the elliptical annulus does not engender any change in the liquid fraction. Inserting nanoparticles is best effective technique to enhance liquid fraction in oblate annulus due to enhanced conduction heat transfer. Use of porous matrix is recommended for prolate and inclined configurations. It obviates considerably stable stratification at bottom of elliptical annulus as a thermal storage unit.