Pure mixed convection inside a vented square cavity with an isothermally heated rotating cylinder

Abstract

A numerical study of two-dimensional, steady-state pure mixed convection heat transfer of air in a vented square cavity with an isothermally heated rotating cylinder has been performed in the present work. Inflow cold air is imposed through an opening (inlet port) at the bottom of the left wall of the vented cavity, whereas the outflow is induced through an exit port of the same size located at the top of the right wall. The circular cylinder is rotating at a constant angular speed with either clockwise (CW) or counter-clockwise (CCW) direction. The mathematical models of the problem representing Navier-Stokes and energy equations have been solved using Galerkin finite element method. To maintain pure mixed convection, Richardson number is fixed at unity, whereas both Reynolds (Re) and Grashof (Gr) numbers are simultaneously varied within the range of 1 ≤ Re ≤ 500 and 1 ≤ Gr ≤ 2.5 × 105 respectively. Moreover, the influence of different positions of the rotating cylinder has been investigated through the visualization of streamline and isotherm plots, and the distribution of the average Nusselt number of the cylinder surface. It is found that heat transfer characteristics strongly depend on the governing parameters, the position as well as the direction of rotation of the cylinder inside the vented cavity.