Heat transfer performance investigation of the spherical dimple heat sink and inclined teardrop dimple heat sink

Abstract

The convective heat transfer is significant in the cooling channel, but the heat transfer enhancement in a cooling passage will be more useful or increases if a dimple is employed on their surfaces. In the case of the nozzle, heat exchanger, the fuel of nuclear reactor and heat sink, the application of the dimple is handy. In the present Investigation, a numerical and experimental investigation has been carried out to study a Nusselt number and the pressure loss performance of a spherical dimple heat sink and inclined teardrop dimple heat sink under different flow conditions. The study is being performed for a Reynolds number varying from 1800 to 7000. To get a reasonable comparison of the dimple heat sink, both the geometries have the same longitudinal spacing of 10 mm, the transverse spacing of 5 mm and dimple depth to dimple diameter ratio of 0.2. Dimple is formed on both the sides of the aluminum heat sink, both inclined teardrop dimple and spherical dimple heat sink exhibit the heat transfer augmentation of about 1.09 to 1.15 times and 1.04 to 1.08 times as compared to the flat heat sink. Inclined teardrop dimple heat sink shows the highest heat transfer of about 8.6% higher than the spherical dimple heat sink. Additionally, friction factor, thermal performance, and flow structure are obtained numerically by using Ansys Fluent software. Inclined teardrop dimple heat sink exhibits the increase of pressure loss of about 3.45% to 4.98% as corresponding to the spherical dimple heat sink.