Effect of the dimple location and rotating number on the heat transfer and flow structure in a pin finned channel

In this study, the Realizable k - epsilon turbulent model combined with the wall enhanced function is used to evaluate the heat transfer and flow structure in a rotating pin finned channel with different dimple locations. The Re number is fixed at 7000. The Ro number is varied from 0 to 1.0. Three different dimple locations are introduced to investigate the effect of the dimple location on heat transfer and flow structure. The streamline, dissipative function and Nusselt number are shown and discussed in this study. A counter-rotating vortex, which is induced by the Coriolis force, is found at the back of the pin fin. It transports wake fluid from the trailing side to leading side. As the dimple moves close to the leading edge of the pin fin, the dissipative function and Nusselt number are increased remarkably. As the Ro increased, the Nusselt number is increased both at the leading side and trailing side. However, the Nusselt number at the trailing side shows a higher growth rate compared to that at the leading side. The lower Nusselt number region at the trailing side wake is also decreased as the Ro increased. The wall shear stress integral is decreased at the leading side while it is increased at the trailing side as the Ro increased. (C) 2018 Elsevier Ltd. All rights reserved.