Boundary condition-enforced immersed boundary method for thermal flow problems with Dirichlet temperature condition and its applications

A boundary condition-enforced immersed boundary method is presented in this paper for simulation of free and forced convection problems with Dirichlet-type boundary condition. The heat source/sink is introduced into the energy equation to model the effect of immersed boundary. Different from previous works, in this paper, the heat source/sink is not pre-calculated, but determined implicitly in such a way that temperature at the immersed boundary interpolated from the corrected temperature field accurately satisfies the thermal condition. The main advantage of the proposed method lies in its simple concept, easy implementation and robustness in stability. Another important contribution of the paper is that it presents two efficient ways to calculate the average Nusselt number. They are based on temperature correction at Eulerian points and heat flux at Lagrangian points, in which no approximation for temperature gradients is needed. Numerical experiments for both forced convection and natural convection problems have been conducted to validate the capability and efficiency of the present method and proposed two ways to calculate the average Nusselt number. Good agreements with available data in the literature have been achieved. (C) 2011 Elsevier Ltd. All rights reserved.