Flow Visualization of the Three-dimensional Mixed Convection in a Horizontal Square Channel with Heated and Cooled Side Walls

Abstract

This paper describes the flow visualization of the three-dimensional mixed convection in a horizontal square channel with heated and cooled side walls by dye-injection method. The working fluid is water. The water temperature at inlet is changed from 10°C to 50°C. Three-dimensional spiral flows are observed along the longitudinal direction of the channel. In the case of 50°C inlet temperature, a pair of spiral flows, clockwise and counter clockwise rotation, are generated across a section. The pitch of the spiral flow decreases with increase of Richardson number Ri(??Gr/Re ² ).