Augmentation of Jet Impingement Heat Transfer of Flat Plate via Humped Roughness Elements

Abdelfattah, Mustafa; Aziz, Mohamed A.; Maghrabie, Hussein M.

doi:10.21608/svusrc.2024.299456.1224

Augmentation of Jet Impingement Heat Transfer of Flat Plate via Humped Roughness Elements

Document Type : Original research articles

Authors

¹ Department of Mechanical Engineering, Faculty of Engineering, Suez University

² Department of Mechanical Engineering, Faculty of Engineering, South Valley University, Qena, Egypt

10.21608/svusrc.2024.299456.1224

Abstract

This study explores the impact of humped roughness elements on heat transfer (HT) in the context of jet impingement. The roughness elements are widely employed across various industrial applications. Numerical simulation using the Re-Normalizations Group (RNG) k-ε turbulence model investigates the HT characteristics of a circular air jet directed onto a surface featuring a circular arrangement of humped roughness elements. The investigation covers a Reynolds number (Re) ranged from 7000 to 35000. The roughness elements are strategically positioned at distances relative to the jet diameter (s/d) of 1.5, 2, 2.5, and 3. The study evaluates the local Temperature distribution (T), the average HT coefficient (havg) and its relative enhancement compared to a smooth plate (havg.r). The findings underscore a significant augmentation in HT performance with the humped configuration, showing havg.r values reaching up to 1.2 times that of the smooth plate case. This enhancement is primarily attributed to the increased HT area and heightened turbulence intensity induced by the presence of the humped roughness elements, thereby facilitating more efficient HT rates.

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