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...
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...
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...
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LIST OF FIGURES
Figure Page
2.1
Typical two-phaseflow patterns in horizontal
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...
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...
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....
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)...
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...
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...