A lattice Boltzmann (LB) method based on the linearized Boltzmann Bhatnagar-Gross-Krook equation for numerical simulation of oscillatory (unsteady) Stokes flow is proposed. Unlike the conventional (nonlinear) LB method that utilizes the time domain exclusively, the proposed method is formulated in the frequency domain to allow for direct access to the complex-valued stress, force, and velocity ...

steam reforming integrated with oxidation of methanol was considered with numerical simulation. the parallel micro-channels with circular cross sections were used. because when the catalytic deposited inside the rectangular micro-channels, it fills up the edges. hence, the approximation of a cylindrical channel is appropriate. effect of this changing in cross section was considered and results ...

We have designed and realised a micromachined micro Coriolis flow sensor for the measurement of hydrazine (N2H4, High Purity Grade) propellant flow in micro chemical propulsion systems. The sensor should be able to measure mass flow up to 6 mg/s for a single thruster or up to 24 mg/s for four thrusters. The sensor will first be used for measurement and characterisation of the micro thruster sys...

In the study of non-equilibrium heat transfer in multiphase flow in porous media, parameters and constitutive relations, like heat transfer coefficients between phases, are unknown. In order to study the temperature development of a relatively hot invading immiscible non-wetting fluid and, ultimately, approximate heat transfer coefficients, a transparent micro-model is used as an artificial por...

The micro-scale gas flows are usually low-speed flows and exhibit rarefied gas effects. It is challenging to simulate these flows because traditional CFD method is unable to capture the rarefied gas effects and the direct simulation Monte Carlo (DSMC) method is very inefficient for low-speed flows. In this study we combine two techniques to improve the efficiency of the DSMC method. The informa...

Description Background – Given the increasingly stringent cooling demands in mid to high-end electronic packages, there is a need for high cooling power density yet robust cooling solutions. Convective liquid cooling using micro-channel heat sinks in single-or two-phase operation has received a lot of attention in recent research. Whereas single-phase cooling is simpler and more robust, two-pha...

The phenomenon of the cementing annulus micro clearance gas channeling directly influences cement job quality and oilfield production, so accurately describing the flow rule of cementing annulus micro clearance gas channeling is the core and "bottleneck" problem of controlling gas channeling effectively. From the perspective of the micro particle motion and based on the lattice Boltzmann method...

Permeability of hot mix asphalt (HMA) is an important property that influences asphalt’s resistance to moisture damage. All current methods used by pavement engineers rely on measuring vertical permeability. However, it has been shown recently that the horizontal permeability can be much higher than the vertical one due to the anisotropic and heterogeneous nature of air void distribution. Labor...

In the last few decades, micro-models have become popular experimental tools for two-phase flow studies. In this work, the design and fabrication of an innovative, elongated, glass-etched micro-model with dimensions of 5 × 35 mm(2) and constant depth of 43 microns is described. This is the first time that a micro-model with such depth and dimensions has been etched in glass by using a dry etchi...