ABSTRACT
Critical heat flux (CHF) of subcooled flow boiling with water in tube with internal twisted tape under circumferentially nonuniform heat flux condition was experimentally investigated using direct current heating of stainless steel tube. The critical heat flux in tube with internal twisted tape under non–uniform heat flux condition was higher than those under uniform heat flux condition. It was explained with the disruption of bubble boundary layer along the twisted tape flow under non–uniform heat flux condition. The boiling curve of high velocity subcooled flow was derived and the net vapor generation heat flux was confirmed to be almost coincided with the Levy model. By assuming the disruption of bubble boundary layer at the lower heat flux part where the heat flux was lower than the net vapor generation heat flux, the increase of the CHF with twisted tape flow under non–uniform heat flux condition was well explained.
