Various flow field designs have been numerically investigated to evaluate the effect of pattern and cross-sectional dimensions channel on performance a large active area PEM fuel cell. Three types multiple-serpentine channels (7-channels, 11-channels 14-channels) chosen for 200 cm2 cell analysed by varying width land channel. The CFD simulations showed that as decreases, in 14-channels serpenti...

Due to high mixing performance and simple geometry structure, serpentine micromixer is one typical passive that has been widely investigated. Traditional zigzag square-wave micromixers can achieve sufficient mixing, but tend induce significant pressure drop. The excessive drop means more energy consumption, which leads low cost-performance of mixing. To mitigate drop, a novel utilizing ellipse ...

A polymer microchannel chip with a symmetrical or unsymmetrical zigzag-side-walled structure was fabricated by an imprinting method, and applied to study shape effects on solution flow characteristics as well as on the liquid/liquid extraction efficiency of an aluminium(III) chelate complex (Al-DHAB: DHAB = o,o'-dihydroxyazobenzene) in a microchannel chip. In an unsymmetrical zigzag-side-walled...

We report in situ environmental transmission electron microscope observations of the nucleation and growth of multi-wall and single-wall carbon nanotubes formed by the catalytic decomposition of acetylene (C2H2) on Ni/SiO2 catalyst. The growth rate, structure and morphology of the carbon nanotubes formed depended upon reaction temperature and pressure. Under 20-100 mTorr of gas pressures at 480...

A long-term hemodialysis patient with a giant intracranial vascular channel, which has been called a giant serpentine aneurysm, is presented. A 50-year-old man with an eight-year history of hemodialysis treatment was admitted because of headache, nausea and double vision. Computed tomographic scans and nuclear magnetic resonance revealed intracranial abnormal shadow. The left vertebral arteriog...

Sample mixing is difficult in microfluidic devices because of laminar flow. Micromixers are designed to ensure the optimal use of miniaturized devices. The present study aims to design a chaotic-advection-based passive micromixer with enhanced mixing efficiency. A serpentine-shaped microchannel with sinusoidal side walls was designed, and three cases, with amplitude to wavelength (A/λ) ratios o...

Motivated by the three-dimensional serpentine channel (Liu et al. in J Microelectromech Syst 9:190–197, 2000), we introduce a chaotic serpentine mixer (CSM) and demonstrate a systematic way of utilizing a mapping method to find out an optimal set of design variables for the CSM. One periodic unit of the mixer has been designed to create two streamlines portraits crossing each other. As a prelim...

• 3D Lattice Boltzmann simulation of the flow on cathode side a micro PEFC at wet and dry operating conditions. X-ray tomographic assessment serpentine channel geometry porous structure GDL. A GDL leads to higher magnitude cross-flows under ribs, transferring gas from one straight next. The normalized local accumulated along are substantially in compared In electrochemically cells, rib will rec...

Reasonable flow channel designs play a significant role in improving the performance of proton exchange membrane fuel cells (PEMFC). The effect zigzag channels with three different numbers turns on PEMFC was investigated this paper. polarization curves, molar concentration oxygen and water, power density were analyzed, numerical results showed that overall significantly better than conventional...