INVESTIGATION OF THE TRANSPORT OF THE BUBBLE PARAMETERS IN AIR/WATER FLOW CONDITIONS

摘要

Studies for the interfacial area transport are being performed to reduce or eliminatethe dependency of the flow regime map in the two-phase flow analysis code. The mechanistic study for the interfacial area needs a lot of understanding for the particle interactions and propagation phenomena of a flow. To investigate the fundamental two-phase flow phenomena and to generate an experimental data base for a modeling, an air/water test is performed in this study. The facility has a cylindrical acryl type test section of which the diameter and height are 80 mm and 10m, respectively. The local bubble parameters are measured by a five-sensor conductivity probe. The main local bubble parameters are the void fraction, bubble velocity, bubble frequency, interfacial area concentration and bubble size. To investigate the transport phenomena of the two-phase parameters, a local probe and an impedance void meter (IVM) are installed at three axial elevations of the test section. (L/D(velence)12.2, 42.2, 100.7) The test range covers 0.5approx2.6 m/s and 0.04approx1.2 m/s of the superficial liquid and gas velocity, respectively, which correspond to the bubbly and slug flow regimes. The local data from the probe are benchmarked by using other instruments to evaluate the data. The measured void fractions were also validated with well known drift flux models. The transport phenomena of various two-phase parameters are analyzed from the experiment data. The data produced in this study will be utilized for the transport modeling of the two-phase flow parameters.