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EPTT 2020
12th Spring School on Transition and Turbulence
ANALYSIS OF CHARACTERISTICS OF HORIZONTAL GAS-LIQUID INTERMITTENT FLOW USING HIGH-SPEED DIGITAL CAMERA
Submission Author:
Carla Nayara Michels dos Santos , SC , Brazil
Co-Authors:
Carla Nayara Michels dos Santos, Sarah Laysa Becker, Celso Murilo dos Santos, Christine Boos, Jonathan Utzig, Marcela Silva, Henry França Meier
Presenter: Carla Nayara Michels dos Santos
doi://10.26678/ABCM.EPTT2020.EPT20-0082
Abstract
Intermittent gas-liquid flows are characterized by the alternating passage between the elongated bubbles that occupy the upper part of the pipe followed by a piston of liquid that occupies practically the entire cross section of the pipe. In horizontal flows, this flow regime occurs in a wide range of flow conditions and is therefore quite common in many industry processes. The intermittent pattern is divided between plug and slug flow and these flows are inherently unstable and complex, which requires detailed knowledge of their characteristics. In this work experimental series of intermittent gas-liquid two-phase flows had been carried out in a 74 mm internal diameter transparent acrylic horizontal pipe. These experiments were carried out with the objective of investigating characteristics such as: length and shape of the elongated bubble and liquid slug or plug, velocity and frequency of the passage of the intermittent structures in different operational conditions. Air and water were used as the test fluids. The flow behavior was recorded using a high speed video camera that was installed in a region of the pipe with developed flow. The plug and slug flow were successfully recorded and classified on the basis of the visualization study from different couples of test condition of superficial water and air velocities. The digital image processing technique was then used to compare the characteristics between plug and slug flow. Analyzing frame by frame, it is possible to extract structural parameters from different plug and slug flow. In this way, it is possible to evaluate the influence of the increase or decrease in the surface velocities of each phase on the flow characteristics.
Keywords
Intermittent flows, Flow structure, Two-phase flow parameters, high-speed image processing