Velocity Characteristics of Turbulent Natural Convection in Convergent-Plates Vertical Channels

Velocity measurements of natural convection in symmetrically and asymmetrically heated convergent-plates vertical channels are presented. In the first case, symmetrical flow, the two channel plates were both kept at a constant temperature higher than the ambient. In the second case, asymmetrical flow, one plate was kept at a temperature higher than 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 zero velocity 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 by the hot side and decelerates by 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 large vortex at the center of the channel.