Simulation of Conjugate Heat Transfer using the Lattice Boltzmann Method

Flow simulation with conjugate heat transfer, which involves fluid flow, conduction, and radiation in solid components, is a critical capability that helps engineers design and evaluate cooling systems for heat-generating components such as brakes, powertrains, batteries, and power electronics for both gasoline and electric vehicles. For this study, we utilize PowerFLOW™, featuring its novel native thermal solver, which models both fluid and solid domains within a single model. For the flow domain, we use the Lattice Boltzmann Method with VLES turbulence modeling based on the RNG k-epsilon method. And for the solid domain, the finite volume method with second-order accuracy for thermal conduction and a surface-to-surface radiation for the surfaces. This approach not only leads to a more integrated and streamlined workflow but also enables an accurate modeling of conduction and radiation. In this study, we demonstrate the accuracy of the conjugate heat transfer simulation methodology for both forced and natural convection cases. For forced convection cases, we compared channel flow with heated mounted cubes, and for natural convection, we simulated a simplified engine bay under soak conditions. Good correlations were observed with test data for both flow configurations.