ICONE11-36075 A STUDY OF BUBBLY FLOW CHARACTERISTICS IN A VERTICAL TUBE USING WIRE MESH TOMOGRAPHY

概要

論文の詳細を見る
For the development of nuclear reactors and the assessment of their safety features, the development of computer code with the high quantity database from the measurement as well as the understanding of the multiphase flow physics are necessary. In this study, the characteristics of bubbly flow in a vertical tube are investigated using Wire Mesh Tomography (WMT). Local void fraction is detected from the dependency of electrical conductivity on the local void fraction. The developed Wire Mesh Sensor is a circular type with two parallel measuring planes to have the capability of gas velocity and bubble size evaluation. The experiment is conducted in a 50mm ID tube at the fully developed condition (93D). The mean bubble size is treated as a constant parameter independent from the superficial gas and liquid velocity by using the bubble generator with a water sub flow. The capability of WMT for studying local characteristic of bubbly flow is presented in Fig 1 and verified by comparing with the literature in Fig 2. In addition, the initial condition effect is still observed at long pipe length. The effects of superficial gas and liquid velocity and the additional bubble intensity on the void fraction distribution are presented. These effects are supposed to change the lateral lift force in both magnitudes and directions which induce the bubble migrated toward to or depart from the wall.
一般社団法人日本機械学会の論文