Numerical simulation of heat transfer and fluid flow around a cylinder of varying cross-section

Abstract

The present paper discusses the effects of geometric parameters on mixed convective heat transfer and fluid flow in a lid-driven square enclosure fitted with an internal elliptical cylinder. The side walls of the enclosure were kept at a cold constant temperature and the lower horizontal wall, and the top moving wall were isolated thermally while the elliptical cylinder wall was sinusoidal heated. The dimensionless equations were solved with the aid of COMSOL Multiphysics software which relies on the finite element method. Simulations were performed for different Grashof numbers 103≤Gr≤105, aspect ratios 1.0≤AR≤3.0, and inclination angle of the elliptical cylinder 0°≤ϕ≤90°. Results are presented in the form of velocity streamlines, isothermal contours, and average Nusselt number. Findings from this study show that the highest heat transfer enhancement occurred when Gr=105. Also, for all the inclination angles and Grashof numbers considered, the more the surface of the ellipse exposed to flow, the greater the heat transfer enhancement. Finally, beyond AR=1.5, inclination angle of the ellipse inhibits heat transfer enhancement.