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Experimental and numerical evaluations of thermal performance in heat exchange channel with punched V-type delta-winglets
Author(s)
Promthaisong, Pitak
Sripattanapipat, Somchai
Nakhchi, Mahdi Erfanian
Skullong, Sompol
Date Issued
September 1, 2026
Type
Article
Abstract
An experimental examination on the heat transmission improvement of a heat exchange channel (HXC) with punched V-shaped delta-winglets (PVDWs) positioned at regular intervals along the heated wall is presented in the article. This channel has a consistent heat flux for the fluid flow with a Reynolds number (Re) between 5295 and 22,700. By producing vortex flows, the PVDWs help to mix the airflow more rapidly, decrease friction loss via the winglets' louver flap, and direct air jets onto the hot-plate wall. PVDWs with three relative pitches (PR = 1, 1.5, and 2) and five louver flap angles (θ = 90°, 60°, 45°, 30°, and 0°) were spaced regularly on the heated surface. The relative winglet height (BR) was maintained at 0.5 and the attack angle was fixed at 45°. Two types of winglet patterns were in use: inline PVDW and staggered PVDW. Thermal effectiveness factor (TEF), Nusselt number (Nu), and friction factor (f) were all influenced by the PVDW parameters. Varieties of θ and PR are examined parametrically. The smallest Reynolds number results in the greatest rise in frictional factor (fR = 75.07), while the largest Reynolds number gives the greatest improvement in heat transfer rate (NuR = 7.63) for I-PVDW at θ = 0° and PR = 1.0. Both the S-PVDW and the I-PVDW reached their maximum TEFs at θ = 45° and PR = 1, with the former reaching 2.67 and the latter 2.63. Nu and f correlations can also be estimated using their measured data. The best thermal effectiveness and lower friction in the test channel are achieved by using S-PVDWs. The predicted findings were validated by the matching measured data after a 3D numerical study was performed to analyze heat transfer and flow patterns using the realizable k-ε turbulence model. Both the experimental and computational results were in good agreement, and the heat transfer mechanism of the PVDW was elucidated. A reconfiguration of the S-PVDW is performed by reversing the flap angle to increase thermal effectiveness. At θ = −45° and PR = 1, the updated S-PVDW shows a highest TEF of 2.78, which is approximately 4% better than the previous analysis.
Citation
International Communications in Heat and Mass Transfer, 178(P3), 2026