Experiments in cap-bubbly two-phase flows for two-group IATE development

T. Worosz, S. Kim

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

    Abstract

    In the two-group interfacial area transport equation (IATE) used to calculate the interfacial area concentration, ai bubbles are categorized into two groups. Namely, group-I consists of spherical/distorted bubbles, and group-II consists of cap/slug/churn-turbulent bubbles. Robust models for the major bubble interaction mechanisms that cause the transition from purely onegroup to two-group flows are essential to the dynamic closure of the two-fluid model with the two-group IATE. Therefore, the present study seeks to establish an experimental database in capbubbly flows that highlights this transition to support model development. A four-sensor conductivity probe is used to obtain measurements of local time-averaged two-phase flow parameters, including the void fraction and ai in vertical-upward air-water two-phase flow in a 5.08cm pipe. Four flow conditions are investigated at <jf>=2m/s with increasing <jg> to study the generation and growth of group-II bubbles. Characteristic features of the local void fraction and ai distributions are discussed. Additionally, axial development of area-averaged void fraction and ai that is indicative of exchange between the bubble groups is presented.

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    All Science Journal Classification (ASJC) codes

    • Nuclear and High Energy Physics
    • Geotechnical Engineering and Engineering Geology
    • Nuclear Energy and Engineering

    Cite this

    Worosz, T., & Kim, S. (2014). Experiments in cap-bubbly two-phase flows for two-group IATE development. In Embedded Topical Meeting on Advances in Thermal Hydraulics, ATH 2014, Held at the American Nuclear Society 2014 Annual Meeting (pp. 302-314). (Embedded Topical Meeting on Advances in Thermal Hydraulics, ATH 2014, Held at the American Nuclear Society 2014 Annual Meeting). American Nuclear Society.