Conjugate natural convection in a vertically divided square enclosure by a corrugated solid partition into air and water regions

The purpose of this study is to investigate conjugate natural convection inside a partitioned differentially heated square enclosure. A corrugated heat-conducting solid partition of three different values of thickness and three different materials is selected. The partition divides the empty spaces of the enclosure into two fluid zones and those zones are filled with air and water, respectively. The governing Navier-Stokes and energy equations are numerically solved by means of the finite element method. The effects of corrugation amplitude, corrugation frequency, thermal conductivity, position and thickness of the corrugated solid partition along with the variation of Rayleigh numbers based on the properties of air on thermal and flow fields have been depicted through contour plots of temperature and stream function, respectively. The average Nusselt number along the hot wall and the average temperatures of both air and water in their respective domains have also been examined to observe the influence of the above variations. The change of corrugation amplitude, thermal conductivity, position and thickness of the corrugated solid partition has considerable effects on heat transfer performance with increasing Rayleigh number. Out of those controlling parameters, it is found that increasing partition thermal conductivity enhances thermal performance by up to 25%. However, the variation of corrugation frequency of the partition as a function of Rayleigh number does not seem to be significant for heat transfer enhancement.