Peculiar effects of permeable tabs on the heat transfer behind the backward-facing step

Abstract

The effect of square-shaped tabs on the turbulent flow dynamics and heat transfer behind the backward-facing step has been studied experimentally. The Reynolds number, calculated by the hydraulic diameter of the inlet section and the average velocity, calculated based on volumetric flow rate was Re = 42500. The 6x6 mm2 square-shaped tabs, installed at the edge of the backward-facing step, were of two types: solid and permeable. The permeable tabs had a square hole of 4x4 mm2 in their center. In the experiments, the spacing between tabs varied from 1.2 to 2.5 calibers. The paper presents the results showing the effect of tabs on pressure distribution, local heat transfer, averaged heat transfer, as well as gives estimates of thermal hydraulic efficiency.