Index Catalog // ScholarsArchive@OSU

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

Stability improvement of the one-dimensional two-fluid model for horizontal two-phase flow with model unification

Creator:: Abel, Kent C.
Abstract:: The next generation of nuclear safety analysis computer codes will require detailed modeling of two-phase fluid flow. The most complete and fundamental model used for these calculations is known as the two-fluid model. It is the most accurate of the two-phase models since it considers each phase independently and links...
Resource Type:: Dissertation
Full Text:: Improvement of the One-Dimensional Two-Fluid Model for Horizontal Two-Phase Flow with Model Unification

A unified model of one-dimension two-fluid horizontal flows and its stability analysis

Creator:: Kim, Dong-Wan
Abstract:: An improved version of the one-dimensional horizontal two-fluid flow model has been developed by incorporating physical terms for gravity and local void fraction profiles. Introduction of an interface mixing layer concept allows the one-dimensional two-fluid model to remain hyperbolic. This will overcomes a major obstacle in using the current one-dimensional...
Resource Type:: Dissertation

Phase distribution parameter determination by neutron radiography

Creator:: Skinner, Jesse B.
Abstract:: A phase distribution parameter has been added to the one-dimensional two-phase horizontal flow conservation equations. The phase distribution parameter was incorporated into the conservation equations in an attempt to add stability and remove correlation switching by incorporating gravity. Determination of the phase distribution parameter requires an average void fraction profile...
Resource Type:: Masters Thesis
Full Text:: A phase distribution parameter has been added to the one-dimensional two-phase horizontal 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

Multiscale modeling of two-phase flows in microarchitectures with microfeatures

Creator:: Truszkowska, Agnieszka
Abstract:: Two-phase flows in microtechnology based devices are purposefully present in multiphase reactors, phase separators, analytical devices and others. Two-phase flows can also be an undesirable side effect occurring during operation due to phase transitions or, more commonly, introduction of surrounding air through equipment gaps and with process feed. In both...
Resource Type:: Dissertation
Full Text:: immis cible liquid systems, can be found in [10]. Two-phase flow solutions for nanoparticle and

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

Synthesis of colloidal metal oxide nanocrystals and nanostructured surfaces using a continuous flow microreactor system and their applications in two-phase boiling heat transfer

Creator:: Choi, Chang-Ho
Abstract:: Metal oxide nanocrystals have attracted significant interests due to their unique chemical, physical, and electrical properties which depend on their size and structure. In this study, a continuous flow microreactor system was employed to synthesize metal oxide nanocrystals in aqueous solution. Assembly of nanocrystals is considered one of the most...
Resource Type:: Dissertation
Full Text:: Nanostructured Surfaces Using a Continuous Flow Microreactor System and their Applications in Two-phase

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

On the effects of centrifugal forces in air-water two-phase flow regime transitions of an adiabatic helical geometry

Creator:: Young, Eric P.
Abstract:: Two-phase flow in helical conduits is important in many industries where reaction between components, heat transfer, and mass transport are utilized as processes. The helical design is chosen for the effects of secondary flow patterns that reduce axial dispersion, increased heat transfer, and also their compact design. The first is...
Resource Type:: Dissertation
Full Text:: Effects of Centrifugal Forces in Air-Water Two-Phase Flow Regime Transitions of an Adiabatic Helical

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

Analyzing the Relationship between Capillary Pressure, Saturation, and Interfacial Area for a Three-Phase Flow System in Porous Media

Creator:: Paustian, Rebecca L.
Abstract:: Multi-phase flow in porous media includes many instances of subsurface flow. Three-phase flow in particular is important in situations of enhanced oil recovery, CO2 sequestration, and groundwater remediation. Many studies have been performed on how two fluid phases (oil/water or air/water) behave in porous media, but very few studies exist...
Resource Type:: Masters Thesis
Full Text:: ............................................................................18 3.2 Two-Phase Flow Experiments

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

Investigating capillary pressure and interfacial area for multiphase flow in porous media using pore-scale imaging and lattice-Boltzmann modeling

Creator:: Porter, Mark L.
Abstract:: Recent advances in imaging technology and numerical modeling have greatly enhanced pore-scale investigations of multiphase flow and transport in porous media. It is now feasible to obtain high resolution 3-dimensional pore-scale data, and numerical methods such as the lattice- Boltzmann (LB) technique have been developed specifically for simulating such phenomena....
Resource Type:: Dissertation
Full Text:: Two Immiscible Fluids . . . . . . . . . . . . . . 13 2.2.2 Richard's Equation for Flow in the Vadose

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