tailieunhanh - Taylor bubble velocity measurements in two - phase air/water vertical flow

The instantaneous velocity of a bubble is expressed as a function separation distance between the two consecutive bubble nose tips (or the position of the center of the bubble). This experimental technique allows studying and measuring with high accuracy both types of flow: full developed and developing slug flows. The major part of this work (experimental set-up, images digitization) is carried out at Kwangju Institute of Science & Technology (KJIST) in Korea. | Vietnam Journal of Mechanics, NCST of Vietnam Vol. 23, 2001, No 3 (183 - 192) TAYLOR BUBBLE VELOCITY MEASUREMENTS IN TWO-PHASE AIR/WATER VERTICAL FLOW T. BUI DINH Institute of Mechanics ABSTRACT. An experimental technique for the measurement of the instantaneous rising velocity of a single Taylor bubble in two-phase air/water vertical flow is proposed. Measurements are based on the multiple successive digital images and binary image processing techniques. The instantaneous velocity of a bubble is expressed as a function separation distance between the two consecutive bubble nose tips (or the position of the center of the bubble). This experimental technique allows studying and measuring with high accuracy both types of flow: full developed and developing slug flows. The major part of this work (experimental set-up, images digitization) is carried out at Kwangju Institute of Science & Technology (KJIST) in Korea. 1. Introduction Gas-liquid slug flow is a flow pattern encountered when the two phases flow simultaneously upward in vertical tube. This flow pattern is characterized by large bubbles, which will be referred to as G. I. Taylor bubbles. This pattern is frequently observed in a variety of industrial situations including geothermal, oil and gas wells and pipelines, process vaporizer and the riser section of boiling nuclear reactors, etc. The motion of Taylor bubbles in liquid flow is a basic phenomenon in slug flow. In general, slug flow is undesirable because of violent pressure fluctuations and hence it is important to investigate the behaviour of Taylor bubbles. The rising velocity of a single Taylor bubble in stagnant and moving liquid in a vertical pipe has been studied by numerous authors, both theoretically as Dumitrescu (1943), Davies and Taylor (1949) , Moissis and Griffith (1962), Barnea and Brauner (1985) , Barnea and Taitel (1993), Mao and Dukler (1990), and experimentally by Griffith and Wallis (1961), White and Beardmore (1962), Nicklin .

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• Vietnam Journal of Mechanics
• Taylor bubble velocity measurements
• Two phase air water vertical flow
• Function separation distance
• Kwangju Institute of Science & Technology
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