Friction and Heat Transfer in Twisted Flow inside a Pipe

摘要

Approximate calculations of the characteristics of heat exchange and friction during turbulent flow in tubes with band-type vortex generators are compared with experimental results obtained on an air unit. Graphs are given for hydraulic friction in tubes with band-type vortex generators, heat exchange in tubes with band-type vortex generators, effect of the Prandtl number on the efficiency of heat exchange in a turbulent flow, and power comparison of band-type vortex generators. The results show that band-type vortex generators are most efficient at relatively small values. On the other hand, wire type spiral vortex generators are more efficient at large values although band-type vortex generators are still preferable at low Reynolds numbers. (Author)