Ajoy Kumar Das

Numerical analysis of characteristic of flow and heat transfer due to natural convection in a enclosure (square) using nano-fluid

The present work discusses, numerical analysis of flow and heat transfer ascribed to natural convection of a heated square cylinder enclosed with a square cylinder keeping two vertical walls as cold wall occupied with nanofluid, water-Al2O3, has been computed by using CFD-Fluent 6.3.26. The effects of parameters such as Rayleigh number, solid volume fraction at aspect ratio (inner cylinder width/outer cylinder width)= 0.2 are examined. It is observed that the heat transfer and flow both effected by Rayleigh Number and solid volume fraction. The results are shown in the form of streamline, isotherm and vorticity contour around the heated square cylinder.

Heat Transfer Enhancement Around a Cylinder – A CFD Study of Effect of Corner Radius and Prandtl Number

Abstract An unsteady two-dimensional laminar forced convection heat transfer around a square cylinder with rounded corner edge is numerically investigated for Prandtl Number, Pr=0.01–1,000 and non-dimensional corner radius, r=0.50–0.71 at low Reynolds number, Re=100. The effect of gradual transformation of square cylinder into circular cylinder on heat transfer phenomenon is studied. The lateral sides of the computational domain are kept constant to maintain the blockage as 5 %. A structured non-uniform mesh is used for the computational domain and the Finite Volume Method (FVM) based commercial software Ansys FLUENT is used for numerical simulation. The heat transfer characteristics over the rounded corner square cylinder are analyzed with the isotherm patterns, local Nusselt number (Nulocal), average Nusselt number (Nuavg) at various Pr and various corner radii. It is found that the heat transfer rate of a circular cylinder can be enhanced 14 % by introducing a new cylinder geometry of corner radius, r=0. 51.