Influence of static bubbles at the surface of electrodes on the natural convection flow for application in high performance lead-acid battery

The natural convection heat transfer is investigated in the cavities which are filled with sulfuric acid-water (25-75%) and with different numbers of generated bubbles at the surfaces of side walls. The heatline visualization approach is employed to detect the heat energy path in the cavity from heat sources to heat sinks. The operating fluid is sulfuric acid-water (25-75%) with constant thermo-physical properties. The Navier-Stokes equations are solved based on two-dimensional form, and finite volume approach is utilized. The side walls are heated with constant/uniform heat flux and no-slip condition is applied to them. The top and bottom walls are cooled by environment temperature with no-slip condition. The influences of different governing parameters of Rayleigh number (10(3) < Ra < 10(5)), and three different numbers of generated bubbles on the heat flux on the flow structure, temperature field, velocity and temperature distributions, average Nusselt number, and heatlines have been presented comprehensively.