Abstract
For making clear the phenomena on the unsteady heat transfer with liquid film in two phase flow, the measurements are needed about unsteady velocity profiles and film thickness in the liquid film adding time-averaged values. It would be important especially to estimate the dry out mechanism of liquid film experimentally on fuel rod around the spacer in the new fuel assembly of BWR. In this study, the unsteady velocity profiles would be estimated by the surface and flow velocity profiles, which were detected experimentally by the tracking of the visualizing particles with image processing. In addition, for estimating of liquid film thickness, we have tried to measure 3D representative velocity profile by main & sub cameras.
