this paper reports a cfd modeling study to investigate the hydrogen-air mixture combustion in a micro scale chamber. nine species with nineteen reversible reactions were considered in the premixed combustion model. the effect of operational and geometrical conditions including; combustor size, wall conductivity, reactant flow rates and hydrogen feed splitting on combustion stability and outlet ...

We demonstrated micro counter-current flow in a glass microchip utilizing surface modification patterning method to control surface tension. In order to visualize the micro counter-current flow, fluorescent microparticle dispersion solutions were observed by fluorescence microscopy. When the flow volume ratio of water and organic solution was changed, the switching point of flow direction was o...

This paper reports on an investigation of mass transport of blood cells at micro-scale stenosis where local strain-rate micro-gradients trigger platelet aggregation. Using a microfluidic flow focusing platform we investigate the blood flow streams that principally contribute to platelet aggregation under shear micro-gradient conditions. We demonstrate that relatively thin surface streams locate...

Microchannel heat sink is fabricated on silicon wafer by anisotropic etching, and used Pyrex #7740 as a transparent cover which integrated by anode bonding. Rectangular microchannel presents the flow phenomena of fluid in micro scale, and this study focus on the boundary conditions which hydraulic diameter (Dh) is from 80mm to 530mm and Aspect ratio is from 0.24~7.8 of working fluid (DI water)....

The determination of flow field properties of large-scale explosions which is necessary for better understanding and flow modeling is rather challenging and difficult. Recent studies show that micro-explosions can be an acceptable substitute. However, quantitative determination of the flow field is still a challenge given the extremely short duration and spatio-temporal evolution of the flow. D...

A number of experiments on fluid flow at the micro/nano-scale have demonstrated that flow velocity obviously deviates from the classical Poiseuille’s law due to the micro forces between the wall and the fluid. Based on an oil–water two-phase network simulation model, a three-dimensional pore-scale micro network model with solid–liquid interfacial effects was established. The influences of solid...

In relation to the time-scale of chemical kinetics, diffusive transport in micro-devices is faster than in conventional mixers. To exploit the resulting potential for chemical process engineering, size effects evident in the transport processes have to be understood. For this purpose, the scaling behaviour concerning the transport of mass, momentum and heat are considered. Just as much, the mix...

We survey the field of micro-macro numerical techniques for predicting complex flows of viscoelastic fluids. The micro-macro approach couples the mesoscopic scale of kinetic theory to the macroscopic scale of continuum mechanics. A numerical solution is sought to the coupled non-linear problem involving the conservation laws and a microstructural model of kinetic theory. Although micro-macro te...

Recent developments concerning the unsteady dynamic forces on a spherical particle at finite Reynolds number are reviewed for solid particles and clean micro-bubble. A particle frequency response function and an energy transfer function are derived for a solid particle or a contaminated micro-bubble in gas or liquid flow. A simple, unified method for estimating the cut-off frequency, or cut-off...

On the basis of the rational analysis about the fluidic property of the system, an ultralow gas flow chemical vapor deposition (CVD) strategy was designed to prepare large-scale horizontally aligned ultralong single-walled carbon nanotube (SWNT) arrays. SWNT arrays could be well obtained under extremely low feeding flow of 1.5 sccm in a 1 in. quartz tube reactor. It was confirmed that the tubes...