"On flexible rectangular strip height on flat plate heat convection" by Yang Yang, David S.K. Ting et al.
 

Title

On flexible rectangular strip height on flat plate heat convection

Document Type

Article

Publication Date

4-1-2020

Publication Title

International Journal of Heat and Mass Transfer

Volume

150

Keywords

Flexible turbulence generator, Heat transfer augmentation, Turbulence

Abstract

A 0.1 mm thick and 12.7 mm wide (W) rectangular flexible strip is experimentally investigated for its effectiveness in boosting the convective cooling from a heated flat plate in a wind tunnel. Three strip height, 25.4 mm, 38.1 mm and 50.8 mm, were explored at a 10 m/s wind, and a Reynolds number of 8500, based on the strip width. The heat transfer results are expressed in terms of Nusselt number normalized by the corresponding unperturbed reference case (Nu/Nuo). To uncover the physics behind the heat transfer enhancement, the turbulent flow characteristics were detailed via a 3D hotwire probe. The 25.4 mm-high strip generated vortex structures closest to the surface, and the largest near-surface-downwash velocity. These attributes result in a better mixing, and thus, heat removal. Therefore, the 25.4 mm-high strip provides the highest Nu/Nuo, with a peak value of approximately 1.76 at 9 W downstream, 0.26 larger than that of the 50.8 mm-high strip.

DOI

10.1016/j.ijheatmasstransfer.2019.119269

ISSN

00179310

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