Heat Transfer in a Channel Installed With Semi-Oval Wing Perforated V-Type Baffles

Abstract

An experimental analysis of the heat transfer mechanism, pressure losses, and thermal performance of channels with semi-oval wing perforated V-type baffles (SOW-PVBs) is presented in this paper. The effects of semi-oval wings with various attack angles (22.5°, 45°, 67.5°, and 90°) and Reynolds numbers (Re = 6,000–24,000) were investigated. The experimental findings revealed that SOW-PVBs with various attack angles (22.5°, 45°, 67.5°, and 90°) yielded lower heat transfer than V-type baffles (VBs, 0°). However, the SOW-PVBs showed an advantage over the VBs with their lower friction losses owing to the presence of perforation. SOW-PVBs with attack angles of 22.5°, 45°, and 67.5° offered higher thermal performance factors (TPF) due to the dominant effect of their lower friction losses. For SOW-PVBs, the Nusselt number (Nu) and friction factor (f) rose as the semi-oval wing attack angle was decreased. With varied semi-oval wing attack angles (22.5°, 45°, and 67.5°) and Re, the SOW-PVBs delivered reduced Nu/Nu s (Nu of SOW-PVBs to Nu of smooth channel), lower f/f s (f of SOW-PVBs to f of smooth channel), and higher TPF than VBs by roughly 0.96–9.98%, 6.75–25.2%, and 0.45–2.62%, respectively. Where subscript “s” is in reference to smooth channel. For the studied range, SOW-PVBs with an attack angle of 45° offered the greatest thermal performance factors, 1.15–1.92, primarily attributed to an optimal tradeoff between improved heat transfer and increased friction losses.