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Filtering by: Subject Two-phase flow Remove constraint Subject: Two-phase flow Degree Field Mechanical Engineering Remove constraint Degree Field: Mechanical Engineering

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  • Void fraction variations in a fractal-like branching channel network

    Creator:
    Cullion, Rebecca
    Abstract:
    Two-phase flow in a fractal-like branching microchannel heat sink may have enhanced heat transfer capabilities over single phase flow in the same branching channel network. In order to exploit this potential, a complete understanding of flow boiling in this geometry is required. The fractal-like geometry is similar to that of...
    Resource Type:
    Dissertation
    Full Text:
    Macroscale Two-Phase Flow . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.3 Microscale Two-Phase

  • Experimental study of two-phase gas-liquid flow in a microscale fractal-like branching flow network

    Creator:
    Kwak, Younghoon
    Abstract:
    Two-phase gas-liquid flows in microscale fractal-like branching channel flow networks were experimentally studied to assess the validity of existing void fraction correlations and flow regimes based on superficial gas and liquid velocities. Void fractions were assessed using two different methods. First, void fraction data were acquired using a High-Speed-High-Resolution (HSHR)...
    Resource Type:
    Dissertation
    Full Text:
    . Title: Experimental Study of Two-Phase Gas-Liquid Flow in a Microscale Fractal-Like Branching Flow

  • Microscale thermal management utilizing vapor extraction from a fractal-like branching heat sink

    Creator:
    Apreotesi, Mario A.
    Abstract:
    It is hypothesized that increases in pressure drop due to vapor generation during boiling in microchannels can be reduced by extraction of vapor at its point of inception. Ultimately, this local vapor extraction decreases the pressure drop required to drive the flow through a fractal-like branching, microchannel flow network within...
    Resource Type:
    Masters Thesis
    Full Text:
    ................................................................................. 100 LIST OF FIGURES Figure Page 2.1 Typical two-phase flow patterns in horizontal

  • The experimental characterization of membrane behavior in two-phase gas extraction

    Creator:
    Cappello, Nicholas C.
    Abstract:
    Understanding the behavior of hydrophobic membranes is important for applications where separating a gas from a liquid-gas mixture is beneficial. For example, in-situ vapor extraction can be used in microscale heat sinks to improve heat transfer and flow stability. In this study, gas is experimentally evaluated flowing through flexible polytetrafluoroethylene...
    Resource Type:
    Masters Thesis
    Full Text:
    insufficient to predict gas extraction flow rates from two-phase mixtures, even when accounting for membrane

  • Modeling convective boiling flow with in-situ local vapor extraction

    Creator:
    Salakij, Saran
    Abstract:
    The pressure drop of convective boiling flow may be reduced by extracting vapor locally since the entire generated vapor does not have to travel through the entire channel length. In this study, the theoretical model was developed to simulate a convective boiling flow through a fractal-like branching microchannel network with...
    Resource Type:
    Masters Thesis
    Full Text:
    2 Literature review 3 2.1 Fractal-like branching flow geometry 3 2.2 Two-phase pressure drop

  • Numerical study of flow maldistribution in microchannels using fully resolved simulation

    Creator:
    Martin, Mathieu Georges Charles
    Abstract:
    This thesis addresses numerical simulation of flow maldistribution in microchannels. Microchannels are often associated with two phase-flows which can generate many problems such as plugging the channel or perturbing the flow. In this study we have used CFD and fully resolved technique to simulate what would happen in the case...
    Resource Type:
    Masters Thesis
    Full Text:
    to solve the two-phase flow problem is crucial. Since the simulation is dealing with both freely

  • Microscale thermal management using membrane vapor extraction

    Creator:
    Apreotesi, Mario A.
    Abstract:
    With the miniaturization of microelectronics and increase of processor speeds in the last few decades, thermal management is drastically affecting overall packaging and system capabilities. Due to the special needs introduced, research focusing on microscale cooling has increased. This study combines the positive characteristics of single- and two-phase flows in...
    Resource Type:
    Honors College Thesis
    Full Text:
    . In the preliminary tests, vapor was extracted from the two-phase flow. Although the preliminary

  • CFD simulation of single-phase and flow boiling in confined jet impingement with in-situ vapor extraction using two kinds of multiphase models

    Creator:
    He, Xiaoliang
    Abstract:
    With continued development of the electronic industry, the demand for highly efficient heat removal solutions requires innovative cooling technologies. A computational fluid dynamic (CFD) study, including heat transfer, is performed for an axisymmetric, confined jet impingement experiencing boiling and coupled with vapor extraction. Boiling occurs at the target surface while...
    Resource Type:
    Masters Thesis
    Full Text:
    negative influence of flow instabilities resulting from two-phase flow within a confined region. A

  • Two-phase fluid break flow measurements and scaling in the advanced plant experiment (APEX)

    Creator:
    Pimentel, David Alan
    Abstract:
    The Oregon State University (OSU) Advanced Plant Experiment (APEX) is a one-fourth height, one-half time scale, reduced pressure integral systems test facility designed to model the long-term cooling capabilities of the emergency core cooling systems of the Westinghouse AP600. This study provides a brief description of the APEX test facility,...
    Resource Type:
    Masters Thesis
    Full Text:
    . Title: Two-Phase Fluid Break Flow Measurements and Scaling in the Advanced Plant Experiment (APEX

  • Performance and flow stability characteristics in two-phase confined impinging jets

    Creator:
    Sabo, Michael D.
    Abstract:
    Advances in electronics fabrication, coupled with the demand for increased computing power, have driven the demand for innovative cooling solutions to dissipate waste heat generated by these devices. To meet future demands, research and development has focused on robust and stable two-phase heat transfer devices. A confined impinging jet is...
    Resource Type:
    Masters Thesis
    Full Text:
    and Flow Stability Characteristics in Two-Phase Confined Impinging Jets. Abstract approved: Deborah

  • Passive pumping in pool and open channel configurations via meso-scale asymmetric surface patterning

    Creator:
    Strid, Logan
    Abstract:
    The research presented in this thesis is a continuation of collaboration between Oregon State University and Auburn University studying the feasibility of passively pumping liquid during boiling in a preferential direction using meso-scaled asymmetric surface patterns. Such a passive phase-change mechanism has great potential for thermal management in spacecraft and...
    Resource Type:
    Masters Thesis
    Full Text:
    advantage of two-phase heat transfer. Two phase heat transfer has the advantage over single-phase heat

  • Modeling in-situ vapor extraction during flow boiling in microscale channel

    Creator:
    Salakij, Saran
    Abstract:
    In-situ vapor extraction is performed by applying a pressure differential across a hydrophobic porous membrane that forms a wall of the channel as a means of reducing the local quality of flow boiling within the channel. As the local quality is reduced, the heat transfer capability can be improve while...
    Resource Type:
    Dissertation
    Full Text:
    . ................................................................................................................19 4. Membrane contact phase for horizontal two-phase laminar-laminar flow in rectangular channel

  • Single Phase and Flow Boiling Heat Transfer and Flow Characterization in Microscale Pin Fin Heat Sinks

    Creator:
    Rasouli, Erfan
    Abstract:
    The ever increasing requirements for heat dissipation in various thermal management applications such as computer chip cooling and high power electronics have necessitated the need for novel thermal management techniques. Thermal management using heat sinks with microscale features is amongst the prominent techniques developed over the past two decades. In...
    Resource Type:
    Dissertation
    Full Text:
    regime, the heat sinks with unsteady flow flapping show higher two-phase heat transfer coefficients