Measurement of interfacial structures in horizontal air-water bubbly flows

Justin D. Talley, Ted Worosz, Matthew R. Dodds, Seungjin Kim

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    2 Scopus citations

    Abstract

    In order to predict multi-dimensional phenomena in nuclear reactor systems, methods relying on computational fluid dynamics (CFD) codes are essential. However, to be applicable in assessing thermal-hydraulic safety, these codes must be able to accurately predict the development of two-phase flows. Therefore, before practical application these codes must be assessed using experimental databases that capture multi-dimensional phenomena. While a large database exists that can be employed to assess predictions in vertical flows, the available database for horizontal flows is significantly lacking. Therefore, the current work seeks to develop an additional database in air-water horizontal bubbly flow through a 38.1 mm ID test section with a total development length of approximately 250 diameters. The experimental conditions are chosen to cover a wide range of the bubbly flow regime based upon flow visualization using a high-speed video camera. A database of local time-averaged void fraction, bubble velocity, interfacial area concentration, and bubble Sauter mean diameter are acquired throughout the pipe cross-section using a four-sensor conductivity probe. To investigate the evolution of the flow, measurements are made at axial locations of 44, 116, and 244 diameters downstream of the inlet. In the current work, only measurements obtained at L/D = 244 are presented. It is found that increasing the liquid superficial velocity tends to reduce both the bubble size and the degree of bubble packing near the upper wall. However, it is observed that the position of the maximum void fraction value remains nearly constant and is located approximately one bubble diameter away from the upper wall. It is also found that the bubble velocity exhibits a power law behavior resembling a single phase liquid turbulent velocity profile. Moreover, the local bubble velocity tends to decrease as the local void fraction increases. Conversely, increasing the gas superficial velocity is found to have little effect on the bubble size or velocity, but increases the bubble packing near the upper pipe wall.

    Original languageEnglish (US)
    Title of host publicationInternational Congress on Advances in Nuclear Power Plants 2012, ICAPP 2012
    Pages2302-2311
    Number of pages10
    Volume4
    StatePublished - 2012
    EventInternational Congress on Advances in Nuclear Power Plants 2012, ICAPP 2012 - Chicago, IL, United States
    Duration: Jun 24 2012Jun 28 2012

    Other

    OtherInternational Congress on Advances in Nuclear Power Plants 2012, ICAPP 2012
    CountryUnited States
    CityChicago, IL
    Period6/24/126/28/12

    All Science Journal Classification (ASJC) codes

    • Energy Engineering and Power Technology
    • Nuclear Energy and Engineering

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