| With the rapid development of modern industry, the problems of environmental and ecological are increasing severely, so energy conservation is very important, and imperative. The application of the heat transfer enhancement technology can not only conserve energy and protects the environment, but also reduce the investment and the operating cost. So the heat transfer enhancement technology is always a very important topic, especially the heat transfer enhancement by the pulsating flow which is studied by researchers from all over the world.In this paper, the heat transfer enhancement by laminar pulsating flow in rectangular grooved channels was experimentally investigated. Effects of Reynolds number, pulsation frequency, pulsation amplitude and groove depth (6mm,9mm and12mm), groove width (12mm,18mm and24mm) on the heat transfer enhancement were studied. And in the experiment section, two pressure points are used to measure its pressure respectively, and we have an analysis on the changes of pressure gradient along with the changes of the pulsating flow.Results show that pulsating disturbance can significantly improve the heat transfer ability of the grooved channel. In the steady state, the local Nusselt number increases with the increase of Reynolds number. In the pulsating flow, the Nusselt number also increases with the increase of Reynolds number. But the Nusselt number in the pulsating flow is higher than the Nusselt number of the corresponding steady-state. The heat transfer enhancement factor first increases and then decreases with the pulsation frequency and the Strouhal number, so there exist an optimal pulsation frequency. The heat transfer enhancement factor is influenced by the groove width and groove depth. The amplitude of pressure gradient increases with the increase of Reynolds number, the pulsation amplitude and the pulsation frequency. |
