A numerical simulation of turbulent flow characteristics through periodic grooves of varying curvatures

For several decades extended surfaces have been used in evaporators, cooling channels, nuclear reactors, turbine blades, and multiple practical thermal devices for enhancement in heat transfer. Pertaining research investigation on extended surfaces in a channel flow consists of sharp geometries for enhancement in heat transfer. However, heat transfer enhancement by sharp geometries is at the expense of pumping power. Therefore, the present study aims to minimize pressure drop and improve heat transfer by providing fillets to the sharp corners of different extended surfaces inside a cooling channel. This is achieved by conducting a numerical investigation of turbulent forced convection through a rectangular channel with rectangular ribs with and without curvatures at the sharp corners. The simulations are performed over varying Reynolds numbers (Re\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Re$$\end{document}) of 6000–36000 where the ratio of groove width to channel height, groove pitch ratio, and depth ratio are kept constant at 1, 2, and 0.5, respectively. Assessment of coefficient of heat transfer, frictional losses, and magnitude of heat enhancement are systematically carried out over a varying radius of curvatures on grooves. The inclusion of curvatures improves the overall heat transfer (characterized by Nu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Nu$$\end{document}) a magnitude of 12% and the overall increment in the magnitude of the heat transfer enhancement factor (characterized by η\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\eta $$\end{document}) is increased by 10%. Further, the magnitude of heat transfer increases with the increase in the curvature radius of the sharp corner geometries. The present study proposes several optimal parameters for the enhancement of heat transfer in a periodic grooved channel that can be used in many practical thermal devices.