The main purpose of this work is to extend the method of capacitance transducers to void fraction measurement and flow regime characterization in a two-phase flow system. The void fraction in an air-water system has been measured using the capacitance meter.
Various flow regimes including bubbly, annular, wavy flows have been investigated.
The superficial air and water velocity have been varied in the range of $0.0\leqq{j_g}\leqq 5.395m/\sec$ and $0.0\leqq{j_f}\leqq 10.115m/\sec$ respectively and void fraction has been varied from zero to unity.
The LCR meter is calibrated by both quick-closing valve method and theoretical calculation.
From the experimental results, relationship between the measured relative capacitance and void fraction are obtained for annular and bubbly flows in the vertical test section, and for wavy flows in the horizontal test section under dynamic conditions.
This result is compared with theoretical prediction.
In addition, various parameters of the capacitance technique, such as (1) flow pattern, (2) strip-type electrode position with respect to a dielectric boundary, and (3) width to gap ratio of a pair of ring type electrodes are examined.
본 논문의 목적은 Capacitance Transducer를 이용하여 기포율을 측정하고 유동 형태를 결정하고자 하는데 있다. 실험은 Vertical Test Section 에서 ring-type 전극을 사용하여 Annular flow 와 Bubbly flow 에 대한 기포율을 측정했으며, Horizontal Test Section 에서는 Strip-type(수평위치, 수직위치)과 Ring-type 전극에 대하여 Wavy flow에 대한 기포율을 측정하였다. Ring-type 전극을 사용하여 Annular flow 에 대한 기포율을 측정한 값과 비교하기 위하여 Schwarz 변환을 이용하여 직접 관계식을 유도하여 이를 Program 화 하였다.
