LBM numerical study on oscillating flow and heat transfer in porous media

Abstract

Oscillating flow and heat transfer in regenerative cryocoolers, are very important for the optimization of cryocooler's performance. A numerical study was conducted in such a system by Lattice Boltzmann Method (LBM), which is an efficiently new way compared to that of the traditional continuum Navier–Stokes method. The simulation work was firstly developed in a two-dimensional empty planar channel, and then followed by porous media. The oscillating flow is driven by a periodic pressure wave, with the isothermal or adiabatic planar wall. A coupled double distribution function model, which is one of the typical thermal LBMs, is used to investigate the thermo-hydrodynamics problem. As a key step, the extrapolation and bounce back schemes are used to treat the boundaries. The simulation results have shown a great effectiveness of the implementation of the LBM in the present study. LBM would serve as a promising method for predicting flow and heat transfer characteristics in regenerative cryocoolers, such as pulse tube cryocoolers. In this work, the effects of the characteristic system parameters on the fluid flow and the heat transfer are investigated. Detailed information for system behavior, especially in porous media, are also included in this paper.