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Full-Text Articles in Engineering
Developments On Wetting Effects In Microfluidic Slug Flow, Rafael M. Santos, Masahiro Kawaji
Developments On Wetting Effects In Microfluidic Slug Flow, Rafael M. Santos, Masahiro Kawaji
Faculty Publications and Scholarship
Wetting effects form a dimension of fluid dynamics that becomes predominant, precisely controllable and possibly useful at the micro-scale. Microfluidic multiphase flow patterns, including size, shape and velocity of fluidic particles, and mass and heat transfer rates are affected by wetting properties of microchannel walls and surface tensions forces between fluid phases. The novelty of this field, coupled to difficulties in experimental design and measurements, means that literature results are scarce and scientific understanding is incomplete. Numerical methods developed recently have enabled a shortcut in obtaining results that can be perceived realistic, and that offer insight otherwise not possible. In …
Gas-Liquid Slug Formation At A Rectangular Microchannel T-Junction: A Cfd Benchmark Case, Rafael M. Santos, Masahiro Kawaji
Gas-Liquid Slug Formation At A Rectangular Microchannel T-Junction: A Cfd Benchmark Case, Rafael M. Santos, Masahiro Kawaji
Faculty Publications and Scholarship
Computational fluid dynamics (CFD) is an important tool for development of microfluidic systems based on gas-liquid two-phase flow. The formation of Taylor slugs at microchannel T-junctions has been studied both experimentally and numerically, however discrepancies still exist because of difficulties in correctly representing experimental conditions and uncertainties in the physics controlling slug flow, such as contact line and velocity slip. In this paper detailed methods and results are described for the study of Santos and Kawaji [1] on the comparison of experimental results and numerical modeling. The system studied consisted of a rectangular microchannel T-junction nominally 100μm in hydraulic diameter, …
Numerical Modeling And Experimental Investigation Of Gas-Liquid Slug Formation In A Microchannel T-Junction, Rafael M. Santos, Masahiro Kawaji
Numerical Modeling And Experimental Investigation Of Gas-Liquid Slug Formation In A Microchannel T-Junction, Rafael M. Santos, Masahiro Kawaji
Faculty Publications and Scholarship
Gas-liquid two-phase flow in a microfluidic T-junction with nearly square microchannels of 113 μm hydraulic diameter was investigated experimentally and numerically. Air and water superficial velocities were 0.018–0.791 m/s and 0.042–0.757 m/s, respectively. Three-dimensional modeling was performed with computational fluid dynamics (CFD) software FLUENT and the volume-of-fluid (VOF) model. Slug flow (snapping/breaking/jetting) and stratified flow were observed experimentally. Numerically predicted void fraction followed a linear relationship with the homogeneous void fraction, while experimental values depended on the superficial velocity ratio UG/UL. Higher experimental velocity slip caused by gas inlet pressure build-up and oscillation caused deviation from numerical predictions. Velocity slip …