کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9641868 511852 2005 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Gas-liquid phase distribution and void fraction measurements using MRI
موضوعات مرتبط
مهندسی و علوم پایه مهندسی انرژی مهندسی انرژی و فناوری های برق
پیش نمایش صفحه اول مقاله
Gas-liquid phase distribution and void fraction measurements using MRI
چکیده انگلیسی
We used a permanent-magnet magnetic resonance imaging (MRI) system to estimate the integral, spatially- and temporally-resolved void fraction distributions and flow patterns in vertical gas-liquid two-phase flow. Air was introduced at the bottom of the stagnant liquid column using an accurate and programmable syringe pump. The air flow rate was in upward vertical direction against the gravity vector. Air flow rates were varied between 1 and 200 ml/min. Bubble formation and detachment at the inlet of the vertical column was non-uniform. The cylindrical non-conducting test tube in which two-phase flow is characterized was placed in a 0.26 T permanent-magnet MRI unit. A roughly linear relationship has been observed for the integral void fraction versus volume flow rate of air through vertical stagnant liquid column. Integral or sample-averaged void fraction was obtained by volume-averaging of the spatially-resolved signals. Spatial averaging was performed in a radial or longitudinal axis of the column. The time-averaged spatially-resolved void fraction has also been obtained for the quasi-steady flow of air in a stagnant liquid column. No great accuracy is claimed as this was an exploratory proof-of-concept type of experiment. Preliminary results show that MRI can indeed provide qualitative and quantitative data and is especially well suited for characterization of averaged transport processes in adiabatic and diabatic multi-phase and/or multi-component flows. Better and faster MRI sequences could improve spatial and temporal resolutions significantly.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nuclear Engineering and Design - Volume 235, Issues 10–12, May 2005, Pages 1163-1178
نویسندگان
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