NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM HORIZONTAL CIRCULAR CYLINDER IN A VENTED ENCLOSURE FILLED WITH NANOFLUIDS

Abstract

In this research, the natural convection heat transfer from the horizontal circular cylinder in a vented enclosure filled with nanofluid is investigated numerically. Governing equations settling in the vorticity-stream function formulation is inclusive in the numerical work, which transformed into fitted body coordinate system. The study covered the following ranges of Rayleigh number 10⁴£Ra£10⁶, nanofluid volume fraction 0£j£ 0.2, enclosure width 1.667£ W/D£ 5, and opening size 0£O/W£1. The effect of Rayleigh number, nanofluid volume fraction, enclosure width, and opening size on the Nusselt number, flow patterns and isotherms were investigated. The result shows that the Nusselt number is proportional with Rayleigh number, opening size and volume fraction of nanofluid and inversely proportional with enclosure width. The isotherms and flow patterns display the temperature and flow behaviors with changing studied variables. The thickness of thermal boundary layer decreases with increasing Rayleigh number for each opening size, enclosure width and nanofluid volume fraction.