The structure of separated flow and heat transfer in a round tube with single detached diaphragm

Abstract

Here we present the results of numerical investigation of the flow structure and turbulent heat transfer obtained in a round tube with a diaphragm of height h and some gap c between the tube and the diaphragm. The value of gap between the diaphragm and tube wall was changed within A = c/h = 0 ÷ 0.33. It was defined that an increased distance between the diaphragm and the tube wall modifies the structure of recirculation zone and eliminates the stagnation areas in the region of secondary vortices. The flow regime, when the values of average heat transfer behind the diaphragm with a gap are higher than the same values for the attached rib, was determined. When increasing the gap height from 0 to 0.33, the 30-% increment in the coefficient of thermal enhancement was achieved.