Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 07, 2019 - November 08, 2019
In a high temperature gradient environment, the nanoparticles often deposit on the wall of the fluid machine due to the thermophoretic effects, resulting in energy loss. Even in a cooler of an exhaust gas recirculation system for an automobile engine, energy loss and a decrease in cooling performance are problems due to the nanoparticle deposition phenomenon. In this study, the effects of the attack angle of the cooling plate on the flow field and the nanoparticle deposition phenomenon were investigated by numerical simulation of the rectangular duct flow with the cooling plate installed. As a result, it was found that when the attack angle was changed from 0 to 90 deg, the pressure loss increased as the attack angle increased, and the heat transfer coefficient tended to increase as the attack angle increased. In addition, a vertical vortex with an axis in the main flow direction and a horizontal vortex with a wide recirculation region, where the flow tends to stagnate, were observed. The lateral vortex is superior in terms of heat transfer characteristics, and the vertical vortex has a trade-off relationship that reduces pressure loss compared to the lateral vortex. In addition, the nanoparticle deposition process did not change regardless of which vortex occurred, but when the vertical vortex occurred, the deposition layer thickness increased.
