Multi-phase Flow Velocity Measurement Technique using Shadow Graphic Images

doi:2012.26.3.61

J. Ocean Eng. Technol. > Volume 26(3); 2012 > Article

J. Ocean Eng. Technol. 2012;26(3):61-65.
DOI: https://doi.org/10.5574/KSOE.2012.26.3.061

Ryu Yong-Uk,Jung Kwang-Hyo

R&D center Hyundai Engineering and Construction Co. Ltd.,Dept. of Naval Architecture and Ocean Engineering Dong-Eui University

다위상 유체 속도 계측을 위한 영상기법 적용

류용욱,정광효

현대건설(주) 연구개발본부,동의대학교 조선해양공학과

Keywords: Multi-phase flows, Bubble image velocimetry, Shadow graphy image technique, Fiber optic reflectometer, Overtopping flows

핵심용어: 다위상 흐름, 기포영상유속측정법, 그림자 영상기법, 광섬유반사율 측정법, 월파유동

Abstract

Air-water flow measurements are of importance for the coastal and ocean engineering fields. Although kinematic investigations of the multi-phase flows have been conducted for long time, velocity measurements still are concerned with many researchers and engineers in coastal and ocean areas. In the present study, an imaging technique using shadowgraphy and fiber optic probe for velocity measurements of air bubbles is introduced. The shadow graphy image technique is modified from the typical image velocimetry methods, and optical fibers are used for the well-known intrusive coupled phase-detection probe system. Since the imaging technique is a non-intrusive optical method from the air, it is usually applied for 2D flows. On the other hand, the double fiber optic probes touch flows regardless of flow patterns. The results of the flow measurements by both methods are compared and discussed. The methods are also applied to the measurements of overtopping flows by a breaking wave over the structure fixed on the free surface.