Abstract
The work presents a numerical study of natural convection of water at its density maximum in a partially active square cavity, nine relatives locations of the partially heated/cooled zone are investigated as well as the effect of different thermal boundary conditions represented as the inversion parameter Two behaviors of average Nusselt number has been detected, at Top–Middle, Top–Bottom, and Middle–Bottom configurations give rise to a maximum Conversely, at Middle–Top, Bottom–Top, and Bottom–Middle configurations that take precedence. A heat transfer correlation based on a geometric parameter describing the locations of the active zone and the density inversion parameter is proposed.