Natural convection of water near its density maximum around a cylinder inside an elliptical enclosure along slender orientation

摘要

A numerical investigation of natural convection of water near its density maximum around a cylinder inside the concentric elliptical enclosure along slender orientation was carried out. The effects of the aspect ratio, the elliptical ratio, the density inversion parameter, and the Rayleigh number were investigated. The typical flow and thermal fields were exhibited by means of streamlines and isotherms, respectively. Variations of the local and average Nusselt numbers were obtained and discussed with the details of both flow and thermal fields. The mechanism of oscillation was also analyzed when the stable flow transits to the unstable flow. Based on the simulation results, the heat transfer correlation has been proposed.