A fractional-step thermal lattice Boltzmann model for high Peclet number flow

As a promising approach in hydrodynamics and thermodynamics modeling, the lattice Boltzmann method (LBM) still suffers severe numerical instability when the temperature field of the flow is convection-dominant (high Peclet number). Despite a lot of research devoted to solve this problem worldwide, to simulate high Peclet number thermal flow at comparably few computational Cost is still a hard work, making it inefficient in practical use. In this paper, we combine the LBM and the fractional-step method to propose a novel and stable thermal lattice Boltzmann scheme for high Peclet number flow without refining the lattice. By numerical tests of thermal Poiseuille flow and Couette flow, we quantify second-order accuracy of the proposed model, and through several cases of Peclet number from low to high, the superior stability and efficiency compared with existing thermal lattice Boltzmann model. (C) 2015 Elsevier Ltd. All rights reserved.