Flow Visualization of Benard-Type Mixed Convection in a Horizontal Square Duct

Abstract

This paper describes the flow visualization of the Benard-type three-dimensional mixed convection in a horizontal square duct with heat transfer bottom wall (T _H=40°C) and upper wall (T _L=20°C) by dye injection method. The working fluid is water. Three-dimensional spiral flows are observed along the longitudinal direction of the duct. Direction of rotation of the spiral flow depends on the difference between the inlet fluid temperature and the symmetrical spiral flows are collapsed in the downstream region.