Velocity characteristics of turbulent natural convection in symmetrically and asymmetrically heated vertical channels

This paper presents the results of velocity measurements of natural convection in symmetrically and asymmetrically heated vertical channels. In the first case of symmetrical flow, the two channel plates were both kept at a constant temperature higher than the ambient. In the second case of asymmetrical flow, one plate was kept at a temperature higher than the ambient temperature while the other plate was kept at a temperature lower than the ambient temperature. The velocity measurements were performed using a Laser Doppler Anemometer. In the case of symmetrical flow, the results indicate a reverse flow region located at the center of the channel close to its exit. In the case of asymmetrical flow, the results show that the flow accelerates up the hot plate and decelerates down the cold plate. The results also indicate that cooling one of the two plates below ambient influences the flow pattern significantly and results in the formation of a small reversed vortex at the center of the channel.