Abstract
Thermal boundary condition of lattice Boltzmann method to simulate natural convection embedded with complex solid object is proposed. This is achieved by denoting the closest nodes adjacent to the boundary in the fluid domain as boundary nodes of the flow domain. The temperature of the boundary node is obtained by linear interpolation between the temperature of the solid object and the second fluid node further away. Then distribution functions originates from the solid domain at the boundary nodes are modified using known distribution functions and correctors to satisfy the momentum and energy. The technique is examined by simulating thermal Couette flow with wall injection, transient thermal flow induced by an abruptly rotating heated ring and nature convection in an annulus between a square outer cavity and a circular inner cylinder. Numerical simulations indicate that this method is second order accurate, and all the numerical results are compatible with the benchmark solutions. © 2012 Elsevier Ltd.