Xu Yousheng

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.

Simultaneous Recovery of Porosity (Porosity Seed) and Total Heat Transmission in Fibrous Porous Materials

We present an inverse analysis of the conductive and radiative heat transfer problem in fibrous porous materials. The porosity and total heat transmission are simultaneously recovered in the finite-volume method and genetic algorithm scheme for both uniform and nonuniform porosity distributions. We solve the heat transfer equations directly to obtain the total heat transmission that defines the objective function to be minimized in the inverse analysis. The results show that the combined scheme is an effective tool for the inverse analysis of fibrous porous materials.