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.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Smith Eiamsa-ard

Smith Eiamsa-ard is a Professor of Mechanical Engineering at Mahanakorn University of Technology, Thailand. He obtained his B.Eng. in Mechanical Engineering from Mahanakorn University of Technology, M.Eng. and D.Eng. in Mechanical Engineering from King Mongkut’s Institute of Technology Ladkrabang, and D.Eng. in Mechanical Engineering from Mie University. He has been working at Mahanakorn University of Technology since 1996. His research interests include thermal and fluid engineering, heat transfer enhancement, and computational fluid dynamics. He is currently working on the application of swirling flow on the heat transfer enhancement, vortex tube, and vortex combustor.

Arnut Phila

Arnut Phila received the D.Eng. in Mechanical Engineering from King Mongkut’s Institute of Technology Ladkrabang, in 2018. He has been working at Mahanakorn University of Technology since 2006. Currently, he is an Assistant Professor of Mechanical Engineering at Mahanakorn University of Technology, Thailand. His research interests include energy technology and management, drying technology, industrial ovens and furnaces, and heat transfer enhancement.

Pitak Promthaisong

Pitak Promthaisong is an Assistant Professor of Mechanical Engineering at Mahasarakham University, Thailand. He obtained his D.Eng. in Mechanical Engineering from King Mongkut’s Institute of Technology Ladkrabang, Thailand. His research works are in computational fluid dynamics, heat transfer enhancement and thermofluid. He is currently working on the application of vortex/swirl flow generators on heat transfer enhancement.

Naoki Maruyama

Naoki Maruyama is a Professor of Regional Innovation Studies at Mie University, Japan. He holds BS and MS degrees in Mechanical Engineering from Mie University in 1986 and 1988, respectively, and become a Doctor of Engineering at Nagoya University, Japan in 1998. His current research interests include heat and flow visualization, two-phase flow, energy conversion, environmental engineering, and life cycle assessment.

Masafumi Hirota

Masafumi Hirota is a Professor of Department of Mechanical Engineering at Aichi Institute of Technology, Japan. He received his D.Eng. in Mechanical Engineering from Nagoya University in 1990, then worked as a Research Associate, Assistant Professor and Associate Professor at Nagoya University, and as a Professor at Mie University, Japan. His research interests include heat exchangers, air conditioning, heat pumps and multiphase flow. His current work is focused on gas–liquid flow in multipass channels, application of airflows in zone air-conditioning and freezing in gas–liquid flow in microchannels.