The Effect of Tube Size and the Length on the Flooding Phenomena Correlations in Vertical Two-Phase Counter-Current Flow

Abstract

One of the prominent problems in the safety analysis of water cooled reactors is the flooding phenomena in the event of an emergency core cooling system operation under the postulated loss-of-coolant accident. In this work the effect of tube size and length on the flooding phenomena in vertical tube was experimentally studied for an adiabatic system. Three different flooding curves were identified In the range studied, significant tube length effect was only observed in smaller tube sizes. For decreasing tube diameters, the system flooded at higher nondimensional gas velocities. The nondimensional pressure gradient also increased with decreasing tube diameter. Results obtained from the tube diameter range of 0.995 cm to 5.08 cm and tube length range of 2.27 m to 3.58 meters are presented.