Lattice Boltzmann Simulation for Complex Flow in a Solar Wall

In this letter, we present a lattice Boltzmann simulation for complex flow in a solar wall system which includes porous media flow and heat transfer, specifically for solar energy utilization through an unglazed transpired solar air collector (UTC). Besides the lattice Boltzmann equation (LBE) for time evolution of particle distribution function for fluid field, we introduce an analogy, LBE for time evolution of distribution function for temperature. Both temperature fields of fluid (air) and solid (porous media) are modeled. We study the effects of fan velocity, solar radiation intensity, porosity, etc. on the thermal performance of the UTC. In general, our simulation results are in good agreement with what in literature. With the current system setting, both fan velocity and solar radiation intensity have significant effect on the thermal performance of the UTC. However, it is shown that the porosity has negligible effect on the heat collector indicating the current system setting might not be realistic. Further examinations of thermal performance in different UTC systems are ongoing. The results are expected to present in near future.