抄録
Many researches used longitudinal vortex to enhance the heat transfer of heat exchanger focus on only the performance of fin plate surface. In this study, the effect of the vortex generators on the heat transfer characteristic on surface of tube was investigated experimentally. The measurement of heat transfer coefficient on the surface of tube and visualization of flow were conducted for three kinds of vortex generators. As a result, using the rectangular wing type vortex generator, the mean Nusselt number on the surface of tube increased about 28%, and using the rectangular winglet type vortex generator, the separation point of tube moved behind the tube by 38°. The generation of longitudinal vortex was seen, but a strong correlation with the heat transfer characteristic of the tube was not able to be confirmed.
