Effect of Aspect Ratio on Convective Heat Transfer for Flat Cross Section Using Nanofluid

For a typical cooling application, enhancement of convective heat transfer greatly depends on tube cross sections. This phenomena was studied by performing numerical simulations on different cross sections for laminar flow with Nanofluids, containing different volume fractions (1%, 2%& 3%) of Aluminum oxide water. Constant axial heat flux with constant peripheral wall temperature i.e. H1 boundary condition was applied and results were validated with existing cross sections. After accomplishing CFD analysis on several cross sections, convective heat transfer coefficient was found highest in case of flat cross section and then the effect of aspect ratio on Nusselt number was investigated. Result shows that Nusselt number increases exponentially with aspect ratio and after reaching a certain aspect ratio, and beyond that Nusselt number becomes constant.