Large-scale heating effects on global parameters for flow past a square cylinder at different cylinder inclinations

Abstract

The combined effects of heating and cylinder inclination on mixed convective flow past a square cylinder subjected to high heating is investigated numerically using a non-Oberbeck-Boussinesq model. A two-dimensional, unsteady, laminar, viscous and compressible flow model is utilized. In order to account for the large-scale heating effects; variations in transport and thermo-physical properties are considered. The flow parameters such as Reynolds number (Re), Prandtl number (Pr), Mach number (M), Froude number (Fr) and free-stream inclination (α) are kept fixed as Re=100,Pr=0.71,M=0.1,Fr=1.0 and α=0o, respectively. The cylinder inclination (ϕ) is varied from 0o to 45o in a step of 10o, while heating levels (ϵ) defined as (Tw−T∞)/T∞ is varied from 0 to 1, in a step of 0.2. The governing equations, in strong conservative form, transformed into body fitted curvilinear co-ordinates, are solved numerically using particle velocity upwind (PVU-M+) scheme employing finite difference method. The effects of cylinder inclination and heating on global parameters such as drag coefficient, lift coefficient, moment coefficient, Strouhal number and Nusselt number are presented. It is observed that for any heating level, mean drag coefficient increases with increase in cylinder inclination. Also at fixed ϕ, mean drag coefficient increases with heating. It is found that in steady flow regime increase in ϕ, decreases the heat transfer rate. In unsteady flow regime, increase in ϕ, increases the heat transfer rate. It is also observed that at fixed cylinder inclination mean Nusselt number increases with increase in heating level.