Polymer Electrolyte Membrane (PEM) fuel cells incorporating microchannels (D<500 μm) can benefit from improved fuel delivery and convective cooling. However, this requires a better understanding of twophase microchannel transport phenomena, particularly liquid-gas interactions and liquid clogging in cathode air-delivery channels. This paper develops optical fluorescence imaging of water films i...

As Digital Microfluidic Biochips (DMFBs) become more and more popular, largescale integration of DMFB microarrays is desirable. Multiple DMFBs with different electrode size from various manufacturers may need to be integrated into a single chip. However, the incompatibility of electrode size poses a problem for the integration of multiple DMFBs. In this paper, a droplet size adapter to convert ...

Computational treatment of immersed rigid bodies, especially in the presence of free surfaces and/or breaking waves, poses several modeling challenges. A motivating example where these systems are of interest is found in offshore wave energy harvesting systems, where a floating structure converts mechanical oscillations to electrical energy. In this study, we take the first step in developing a...

To determine how fracture–vuggy structure, pressure, and injection–production mode influence displacement efficiency in the water flooding process in fracture–vuggy reservoirs, two types of models were built based on the characteristic of such reservoir: two fracture models with different fracture apertures and two fracture– vuggy models with different sizes of vugs. A series of twophase fluid ...

We present a nonlinear model predictive framework for closed-loop control of twophase flows governed by Cahn-Hilliard Navier-Stokes system with variable density. The control goal consists in achieving a prescribed concentration distribution in the Cahn-Hilliard part through distributed and/or boundary control of the flow part. Special emphasis is taken on quick control responses which are achie...

This paper presents performance evaluation of an asymmetrical parameter type two-phase induction machine drive using two-phase three-leg voltage source converter (VSC) operating in motoring and generating modes. A system is simulated using MATLAB/SIMULINK. The proposed converter system includes a machine side converter using a three-leg VSC and a front end converter using a single-phase full br...

The effect of initial bubble diameter on the motion pattern in a flotation column has been studied by twophase computational fluid dynamics (CFD) method. two-phase simulations have done using volume (VOF) model ANSYS® Fluent® software. field was square cross-section with width 0.1 m and height 1 into which air interred as single from lower part an internal sparger. An experimental test also per...

In this first part of a two-part study, experiments were performed to investigate condensation of FC-72 along parallel, square micro-channels with a hydraulic diameter of 1 mm and a length of 29.9 cm, which were formed in the top surface of a solid copper plate. The condensation was achieved by rejecting heat to a counter flow of water through channels brazed to the underside of the copper plat...

In this paper we investigate scale-dependent radial two-phase flow of liquid and gas in unsaturated porous media. First we present an equation of two-phase flow of liquid and gas in porous media in radial coordinates (ETPR) based on McWhorter’s equation in Cartesian coordinates. Then we present three analytical solutions for the ETPR: [1] an exact solution of ETPR in three dimensions for radial...