Heat transfer characteristics of jet impingement on a surface mounted with ribs using LES

Abstract

The present study investigates flow and heat transfer features of jet impingement on a surface fitted with detached ribs at Re = 20,000 using OpenFOAM 4.1 based large eddy simulation (LES). The WALE SGS model is applied. A wall resolved simulation is performed to understand the flow behaviour and heat transfer enhancement in the impingement regions and ribs. The WALE model is observed to be suitable for accurate calculations of complex application-based flow configurations. A comprehensive discussion on flow physics is carried out to understand heat transfer in the rib regions and the effects of flow and turbulence parameters. The investigation reveals that augmentations in the velocity and turbulence are directly linked to the local heat transfer enhancement in the clearance between the ribs and heated plate. A dual peak exists for turbulence kinetic energy profiles. The local heat transfer is observed to be maximum in the clearance region between the second rib and plate. The region of maximum local heat transfer was observed to be related to the peak velocity and turbulence kinetic energy in the same region. The present computation is capable of capturing small-scale dynamics and turbulence structures. The present results may be utilized in testing RANS-based turbulence models and the findings are useful for researchers and engineers working on EV, HPC and related cooling industries where high localized cooling is required.