This paper employs the volume of fluid (VOF) method to numerically investigate the effect of the width, height, and contact angles on burst frequencies of super hydrophilic and hydrophilic capillary valves in centrifugal microfluidic systems. Existing experimental results in the literature have been used to validate the implementation of the numerical method. The performance of capillary valves...

– Numerical simulation of hydrocyclones aiming at investigating the separation of microorganisms and mammalian cells was performed using Computational Fluid Dynamics (CFD). The turbulence model used in the 2daxisymmetric calculations was the Reynolds Stress Model (RSM), in order to take into account the high swirl effects that occur in this type of equipment, which induce anisotropic turbulence...

The numerical investigation of drop deformation and breakup under simple shear is a basis for theoretical studies of emulsification and mixing. A three-dimensional Couette flow without gravity is considered; the matrix liquid is bounded at the top and bottom by two parallel horizontal plates and the liquid drop is suspended there. The boundaries move horizontally, and generate a simple shear fl...

In this research, hydrodynamics of the Bubble Train Flows (BTF) in circular capillaries has been investigated by Direct Numerical Simulation (DNS).The Volume of Fluid Based (VOF) interface tracking method and streamwise direction periodic boundary conditions has been applied. The results show that there exists an appropriate agreement between DNS and experimental correlation results. The re...

Droplet motion is important in discrete microfluidic operations as well as in emerging site-specific cooling techniques based on electrowetting. The present work reports on carefully characterized experiments that map the shape, advancing and receding contact angles, and contact area of droplets sliding under gravitational actuation as a function of droplet size and velocity. A pseudo-Lagrangia...

gas-lift pumps are devices for lifting liquid phase incorporating the gas phase to be injected in the bottom of liquid column. they are widely used in various industrial applications such as oil extracting in petroleum industries. gas-liquid flow being the main part of the flow through these systems, flowing in vertical pipes of gas-lift pumps has different regimes namely bubbly, slug, churn an...

There are only limited reports on vanadium(iv) oxyfluorides (VOFs) with extended crystal structures. Here we expand and enrich the list of existing VOFs with a series of 14 new materials "VOF-n (n = 1-14)" prepared using ionothermal and solvothermal synthesis methods. All of these materials arise from the condensation of a dimeric structural motif. These VOFs can be classified into three groups...

This paper proposes a comparison of four popular interface capturing methods : the volume fluid (VOF), standard level set (SLS), accurate conservative (ACLS) and coupled (CLSVOF). All are embedded into unified low-Mach framework based on Cartesian-grid finite-volume discretization. includes sharp transport interface, well-balanced surface tension discretization consistent mass momentum which al...

The paper describes a novel implementation of the piecewise linear interface-capturing volume-of-fluid method (PLIC-VOF) in axisymmetric cylindrical coordinates. principal innovative feature involved this work is that both forward and inverse reconstruction problems are solved analytically, resulting an appreciable speed-up computing time comparison with iterative approach. All formulae introdu...

When a hydrogen or oxygen bubble is created on the surface of an electrode, micro-convective vortex flow due to Marangoni effect generated at bottom in contact with electrode. In order study such phenomenon numerically, it necessary be able simulate tension variations along liquid-gas interface, integrate mass transfer across interface from dissolved species present electrolyte gas phase, and t...