Effect of Various Ribs on Heat Transfer and Mixing at the Jet Impingement Wall for Cooling Loss Reduction

Abstract

Direct numerical simulations were performed to investigate the effects of various ribs on heat transfer and mixing at the jet impingement wall. Increasing the number of ribs installed perpendicular to the main flow enhanced mixing in the height direction because the ribs prevented mass transfer along the wall near the jet impingement area. For turbulent heat transfer near the wall, heat transfer suppression at the lower wall was observed when the number of ribs was increased. On the other hand, the area of the top and side surfaces of the ribs increased, but the heat flux at these surfaces decreased, resulting in a minimum total heat transfer at a certain number of ribs.