CFDCalculationforTwo-PhaseFlowinConcentric.docVIP

CFD Calculation for Two-Phase Flow in Concentric Annulus with Rotating Inner Cylinder Yoichi Shiomi, Shigeyasu Nakanishi and Hiroaki Kutsuna Department of Mechanical and System Engineering, Faculty of Science and Technology, Ryukoku University Seta, Otsu 520-2194, Japan Tel: +81-77-543-7458 Fax: +81-77-543-7457 E-mail:  HYPERLINK mailto:shiomi@rins.ryukoku.ac.jp shiomi@rins.ryukoku.ac.jp Date : 27 March, 2000 Computer and operating system used : Sony VAIO PCG-803(Pentium II 230MHz), Windows98 Date of issue of PHOENICS version used : the 31.01.99 version of PHOENICS 3.2 Abstract Calculations have been carried out using the PHOENICS for two-phase flow in a concentric annulus with a rotating inner cylinder. The flow in such system for the single-phase flow is well known as the Taylor-vortex flow. The two-phase Taylor-vortex flow has quite interesting characteristics in experiments. With increasing of the rotating inner cylinder, bubbles agglomerate and make spirals or rings owing to the Taylor-vortex. According to the flow visualization of a cross section in the annulus, the bubbles of spirals or rings locate at very close to the rotating inner cylinder and at out-flow region. Calculations carried out to confirm these characteristics and investigate in detail. Two-phase Taylor-vortex flow was calculated in two dimensional cylindrical coordinate with IPSA method. The original k-? and k-? RNG models are used as the turbulent model. It is confirmed that the Taylor-vortex is obtained in this calculation by the vector of liquid phase. From the void fraction distribution, bubbles exist close to the inner cylinder and locate at out-flow region as same as the experimental results. The calculated results agree with the experimental results qualitatively but we do not obtain the quantitative agreements. 1. Introduction Fig.1 Experimental apparatus The flow in a concentric annulus with a rotating inner cylinder for the single-phase flow is well known as the Taylor-vortex