Pressure Stratification Effects on Multiphase Transport Across a Vertical Slot Porous Insulation

In this work, thermal stratification effects on heat and mass transfer in a porous insulation are analyzed. The vertical boundaries of the porous system are partially permeable for simulating holes or cracks in wall. Hydrostatic pressure variations are considered on the vertical boundaries and a set of realistic boundary conditions is imposed on the system under consideration. The transient intercoupled equations governing the complicated transport process along with the convective boundary conditions are solved by an efficient numerical scheme. The dependence of the Nusselt number and the field variables on several important parameters is investigated systematically. The results clearly show that infiltration can have a major effect on the overall heat transfer even for small pressure gradients across the insulation slab. Furthermore, it has been found that the opening locations have a pronounced effect on the heat transfer rate across the slab and the corresponding condensation rate. The qualitative information extracted from this investigation can be used to diminish the infiltration and condensation problems in the design of building insulation.