Experimental study of gas-liquid flow patterns and void fraction in prototype 5 × 5 rod bundle channel using wire-mesh sensor

Abstract

In this paper, the wire-mesh sensor (WMS) has been successfully introduced into a typical pressurized water reactor (PWR) prototype 5 × 5 rod bundle channel. Combined with the high-speed camera, the typical flow patterns and phase distribution of air–water two-phase flow in the rod bundles are experimentally studied. The gas superficial velocity is 0.020 ∼ 1.102 m/s and liquid superficial velocity is 0.041 ∼ 1.604 m/s. The results indicate that the WMS can accurately identify bubble, cap bubble, cap churn and churn flow. Due to the influence of the wall effect, flow patterns between the subchannels of the rod bundle channel are not completely consistent with the global flow pattern. After evaluating the existing drift-flux models, new correlations of distribution parameter and drift velocity for different flow patterns in rod bundle channel are proposed, which shows a good prediction capability.