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Filtering by: Dspace Collection Electronic Theses and Dissertations Remove constraint Dspace Collection: Electronic Theses and Dissertations Degree Field Mechanical Engineering Remove constraint Degree Field: Mechanical Engineering Subject Microfluidics Remove constraint Subject: Microfluidics

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  • Single- and multi-functional arrayed microchannel fluidic devices

    Creator:
    Fisher, Luke W.
    Abstract:
    Novel fluidic devices that utilize an array of microchannels to achieve their designed purpose are discussed. Examples of devices include: fuel reforming using Microreactors, chip cooling using microchannel heat sinks, and microchannel devices used for biological applications. The devices that have directly contributed to this research include: a microchannel water...
    Resource Type:
    Masters Thesis
    Full Text:
    occasions and also provided a wealth of insight on these research projects. Both of these individuals have

  • Hydrodynamics of droplet impingement on heated surfaces : effects of nanofluid and nano-structured surface

    Creator:
    Shen, Jian
    Abstract:
    This study investigates the hydrodynamic characteristics of droplet impinging on heated surfaces using High Speed High Resolution (HSHR) imaging and evaluates the effect of surface temperature and using water and a nanofluid on a polished and a nano-structured surface. Three types of surfaces are used in the study: polished silicon,...
    Resource Type:
    Dissertation
    Full Text:
    important parameter that many models predict ([7], [23], [24] and [25]). These models are based on surface

  • 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:
    pressure was modified and the code rerun. This process was repeated until the exit pressures agree. These

  • Study of a constrained-film bubble absorber under cycle operating conditions

    Creator:
    Cardenas, Ruander
    Abstract:
    An experimental and numerical study of absorption of ammonia vapor bubbles into a constrained thin film of ammonia-water solution is presented in the context of a potential reduction in size of a heat-actuated heat pump component. A large-aspect-ratio channel with a depth of 600 µm restricts the thickness of the...
    Resource Type:
    Masters Thesis
    Full Text:
    . These two cycles are shown respectively in Figs. 1 and 2. 3 Figure 1: Vapor

  • Applications of the thermal wave technique in liquid thermal conductivity measurements and flow field diagnostics

    Creator:
    Wang, Zhefu
    Abstract:
    The thermal wave technique has been explored for the use of liquid thermal conductivity measurement and flow property diagnostics in this dissertation. For liquid thermal conductivity measurements, an experimental technique based on the thermal wave approach is developed. A stainless steel strip functions as both a heating element and a...
    Resource Type:
    Dissertation
    Full Text:
    thermal conductivity measurement and flow property diagnostics in this dissertation. For liquid

  • 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:
    to 2.5 g/min and from 5.2x10-5 g/min to 1.3x10-2 g/min, respectively. These flow rates yielded

  • Characterization of flow boiling in a fractal–like branching microchannel network

    Creator:
    Edward, Lee M.
    Abstract:
    Based on experimental investigations the present study evaluates flow instability and void fraction in a fractal-like branching microchannel network with rectangular cross-section. The hydraulic diameter of the channels ranged from 308μm at the inlet to 143μm at the outlet. The flow network used is characterized by set branching ratios for...
    Resource Type:
    Masters Thesis
    Full Text:
    between the air core of the channel and the wall of the channel. Generally these bubbles appear to

  • A technique for spatially resolved wall temperature measurements in microchannel heat sinks using infrared thermography

    Creator:
    Krebs, Daniel P.
    Abstract:
    A non-intrusive measurement technique for direct quantitative thermal visualization of channel wall temperatures in two phase microchannel flows using infrared thermography (IRT) is presented. Specifically, the measurement of top channel wall temperatures in a fractal-like branching microchannel silicon heat sink during flow boiling is demonstrated and thoroughly documented. Obtaining quantitative...
    Resource Type:
    Masters Thesis
    Full Text:
    overall miniaturization of electronic components and a near exponential growth in required heat flux

  • Proportional integral derivative control of an oil-heated fractal-like branching microchannel desorber

    Creator:
    Davis, Keith R.
    Abstract:
    A PID controller was designed to control the performance of an oil-heated fractal-like branching microchannel desorber for use in an ammonia-absorption refrigeration system. Both the amount and concentration of ammonia refrigerant generated at the desorber can be controlled by choosing the rectified circulation ratio as the controlled variable in a...
    Resource Type:
    Masters Thesis
    Full Text:
    -Input Single-Output (SISO) models, these systems require more complicated controllers and more

  • 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:
    relatively uniform and stable temperature. Due to the special needs introduced by these new applications