Flow and Heat Transfer Around the Flat Plate Installed in a Rectangular Duct with Flow Pulsation

摘要

This study deals with flow behavior and associated heat transfer in pulsating duct flow. Using of pulsating flow is one of the promising ways for further improvements of various kinds of thermal devices with higher controllability of their temperature. As well as engineers of thermal devices, researchers in bioengineering field also focus on heat and mass transport characteristics of pulsating flow from the viewpoint of life science. Hydrogen bubble method and color schlieren method were employed for the visualization of flow and temperature fields, respectively, in order to investigate the effect of flow pulsation on convection heat transfer. As the experimental results, mechanism of heat transfer enhancement or prevention by flow pulsation was revealed. Various scales of vortices were generated and flow became unstable due to temporal and spatial periodic velocity fluctuations. From these results, it is concluded that heat transfer enhancement or prevention depends on the character of generation of vortices with different scales by the velocity fluctuations.