Hybrid Lattice-Boltzmann simulation of convective flow in a channel with extended surfaces

Abstract

Laminar convective flow in a channel with extended surfaces mounted at the bottom wall is investigated by using two methods. First, by the usual double-population SRT lattice Boltzmann method (LBM) and second by a hybrid scheme in which the flow is solved by single population LBM and the thermal field by the finite-difference (FD) technique with considering an appropriate coupling among them. Here, the iterative method has been chosen in order to solve the discretized energy equation with finite-difference. The transient Reynolds number for the condition of this study was determined to be 600 and all simulations were conducted in the laminar range of Reynolds numbers. It is shown that for CFD problems in which the steady state solution is desired or for those with time consistency it is possible to save computation time of the simulation remarkably by employing the aforementioned hybrid scheme. For the case study of this work, the hybrid scheme resulted in reduction of 18 percent of total simulation time.