Thermal analysis of a cell of lead-acid battery subjected by non-uniform heat flux during natural convection

Abstract

To model a cell of a lead-acid battery, a simplified configuration as similar as a cell is considered, and different governing parameters are studied during convective flow inside the cell. In this context, a numerical analysis on natural convection heat transfer within a rectangular cavity filled with two immiscible fluids, air and acid sulfuric-water (25–75%), with four different profiles of uniform and non-uniform heat fluxes from side walls and different aspect ratios of enclosure is carried out. The profiles of heat fluxes are constant, linear, second order and square root function. Also, the aspect ratios of enclosures are equal to 5, 10, 15 and 20. The Rayleigh numbers are in the range of 103 ≤ Ra ≤ 105 . The streamlines, isotherms, heatlines, average Nusselt number and the skin friction coefficient are presented. The results show that the profile of heat flux has significant influence on the heat transfer rate, average Nusselt number, fluid flow and isotherms within the enclosure.