Thermal Performance Analysis for Laminar Forced Convection in a Square Channel with PD-RWVG

Abstract

The numerical investigation on heat transfer characteristics, flow configurations and thermal evaluations in a square channel with 30o pointing–downstream rectangular winglet vortex generators (PD–RWVG) is presented. The RWVGs are placed on both the upper and lower walls of the square channel with in–line arrangement. The different RWVG lengths, t/W=0.1 – 0.9, with single blockage ratio, b/H = BR = 0.15, and pitch ratio, L/H = PR = 1, are investigated in three dimensional for Reynolds number based on the hydraulic diameter of the square channel, Dh, Re = 100 – 1000. The finite volume method and periodic boundary apply for the current computational domain. The numerical results are reported in three parts; flow configurations, heat transfer characteristics and performance evaluations. In the part of performance evaluations, the heat transfer, pressure loss and thermal performance are presented in forms of Nusselt number ratio (Nu/Nu0), friction factor ratio (f/f0) and the thermal enhancement factor (TEF), respectively. At similar conditions, the use of the channel equipped with PD–RWVG consistently results in higher heat transfer rate and friction factor than those of the smooth channel. The increases of t/W value and Reynolds number result in the rising heat transfer rate and friction factor. The highest Nu/Nu0 of 6.23, f/f0 of 9.3 and TEF of 2.96 are obtained at t/W = 0.90, Re = 1000.