Study of heat transfer by natural convection of nanofluids in a partially heated cylindrical enclosure

Abstract

In this research, a numerical study was carried out on heat transfer by natural convection of two nanofluids in a partially heated horizontal cylindrical enclosure. The partial heating occurs through the lower side of the enclosure at a constant temperature. The length of the heat source is changed from 5% to 25% of the total perimeter of the enclosure. The two side parts of the enclosure are maintained at a low constant temperature, each one of them has a length of 25% of the total perimeter. The top part of the enclosure is considered as adiabatic, it has a length of 25% of the total perimeter. The two nanofluids used are Cu-water and TiO2-water with a volume fraction of nanoparticles being varied in the range of 0–0.05. The Rayleigh number was varied in the interval 103 to 106. The results obtained were summarized in the form of correlation equations of the average Nusselt number as a function of the heated length, the Rayleigh number and volume fraction for both types of nanofluids.

Keywords

• Natural convection
• Horizontal cylindrical enclosure
• Partial heating
• Finite volume
• Nanofluid