Three-dimensional Simulation And Hydrodynamic Characteristics Of Taylor Flow In A T-junction Microchannel

This research was focused on3D numerical simulation of Taylor flow in a squaremicrochannel. The hydrodynamic characteristics of Taylor flow was detailed studiedwith reasonable mesh resolution and boundary conditions. The effect of the thirddimension on the liquid film thickness of Taylor flow in a rectangular cross-sectionmicrochannel was also investigated.Series of simulations on air-water Taylor flow were performed for a T-junctionmicrochannel by using the VOF model in FluentTM. A kind of gradient mesh approachand three kinds of mesh resolutions were proposed to achieve the balance between thenumerical accuracy and computational efficiency for capturing the liquid film.Considering the symmetry of the square channel, a strategy and boundary conditionswere proposed to simulate a half of the channel. The symmetry model was validatedby examining the hydrodynamic characteristics of Taylor flow. The numerical resultsobtained from our simulations agreed well with existing empirical correlations andexperimental measurements reported in the literature.Based on the established simulation methods, the liquid film thickness of Taylorflow in a rectangular cross-section microchannel was further investigated. Thecomparison of liquid film thickness of Taylor flow between channels with squarecross-section and those with circular cross-section was performed. It wasdemonstrated that the non-uniform liquid film along the perimeter caused by thenon-uniform pressure distribution within a square microchannel cannot be describedby the circular tube correlations. Through analyzing the relationship between2D and3D simulation, the influence of aspect ratio on liquid film thickness was furtherinvestigated.