Numerical study on the flow and heat transfer characteristics in a dimple cooling channel with a wedge-shaped vortex generator

Abstract This study numerically investigates the detailed flow structure and heat transfer characteristics of a newly designed dimple cooling channel. The proposed surface geometry is a general dimple structure combined with a wedge-shaped vortex generator on the upstream dimple. The main purpose of the surface geometry is to enhance the flow mixing and heat transfer in the flow-recirculating region that is generated by the dimple cooling channel. Direct numerical simulations were carried out with a Reynolds number of 2800 and Prandtl number of 0.71 in the cooling channel. The main design parameter is the width ratio between the cooling channel and vortex generator ( W * ). When W * increases, the heat transfer on the surface is enhanced because of the main counter-rotating vortex downstream of the computational domain. In the case of W *  = 0.4411, the volume goodness factor increases to approximately 30% compared to the general dimple cooling channel.