Lattice Boltzmann Simulation of Micro Poiseuille Flow in Curved Rough Channels

2009 ◽  
Author(s):  
Weizhong Li ◽  
Wenning Zhou
Keyword(s):  
Lattice Boltzmann ◽  
Specular Reflection ◽  
Lattice Boltzmann Model ◽  
Solid Boundary ◽  
Gas Flows ◽  
Curved Channel ◽  
Roughness Effect ◽  
Lattice Boltzmann Simulation ◽  
Boltzmann Model ◽  
Bounce Back

This paper studies the roughness effect of the two-dimensional micro Poiseuille gas flows in a curved channel by a modified lattice Boltzmann model. A method relating to the Knudsen number (Kn) with the relaxation time is discussed. In addition, to capture the slip velocity on a solid boundary more accurately, a combined boundary scheme (CBC), which combines the no-slip bounce-back and the free-slip specular reflection schemes, is applied to boundary condition treatment. The rough wall of the micro-channel is described by uniformly distributed rectangular or triangular rough elements. The simulation results show that the roughness and the geometries of the channel have great effects not only on velocity distribution but also on pressure distribution.

Modeling of collapsing cavitation bubble near solid wall by 3D pseudopotential multi-relaxation-time lattice Boltzmann method

2017 ◽  
Vol 232 (3) ◽  
pp. 445-456 ◽  
Author(s):  
Minglei Shan ◽  
Yu Yang ◽  
Hao Peng ◽  
Qingbang Han ◽  
Changping Zhu
Keyword(s):  
Relaxation Time ◽  
Lattice Boltzmann ◽  
Cavitation Bubble ◽  
Solid Wall ◽  
Three Dimensional ◽  
Lattice Boltzmann Model ◽  
Bubble Collapse ◽  
Lattice Boltzmann Simulation ◽  
Boltzmann Method ◽  
Boltzmann Model

Understanding the dynamic characteristic of the cavitation bubble near a solid wall is a fundamental issue for the bubble collapse application and prevention. In the present work, an improved three-dimensional multi-relaxation-time pseudopotential lattice Boltzmann model is adopted to investigate the cavitation bubble collapse near the solid wall. With respect to thermodynamic consistency, Laplace law verification, the three-dimensional pseudopotential multi-relaxation-time lattice Boltzmann model is investigated. By the theoretical analysis, it is proved that the model can be regarded as a solver of the Rayleigh–Plesset equation, and confirmed by comparing the results of the lattice Boltzmann simulation and the Rayleigh–Plesset equation calculation for the case of cavitation bubble collapse in the infinite medium field. The bubble collapse near the solid wall is modeled using the improved pseudopotential multi-relaxation-time lattice Boltzmann model. We find the lattice Boltzmann simulation and the experimental results have the same dynamic process by comparing the bubble profiles evolution. Form the pressure field and the velocity field evolution it is found that the tapered higher pressure region formed near the top of the bubble is a crucial driving force inducing the bubble collapse. This exploratory research demonstrates that the lattice Boltzmann method is an alternative tool for the study of the interaction between collapsing cavitation bubble and matter.

ROUGHNESS EFFECT OF DIFFERENT GEOMETRIES ON MICRO GAS FLOWS BY LATTICE BOLTZMANN SIMULATION

2009 ◽  
Vol 20 (06) ◽  
pp. 953-966 ◽  
Author(s):  
CHAOFENG LIU ◽  
YUSHAN NI ◽  
YONG RAO
Keyword(s):  
Surface Roughness ◽  
Lattice Boltzmann ◽  
Experimental Studies ◽  
Resistance Coefficient ◽  
Lattice Boltzmann Model ◽  
Gas Flows ◽  
Fractal Boundary ◽  
Roughness Effects ◽  
Roughness Effect ◽  
Relative Roughness

The roughness effects of the gas flows of nitrogen and helium in microchannels with various relative roughnesses and different geometries are studied and analyzed by a lattice Boltzmann model. The shape of surface roughness is simulated to be square, sinusoidal, triangular, and fractal. Numerical computations compared with theoretical and experimental studies show that the roughness geometry is an important factor besides the relative roughness in the study of the effects of surface roughness. The fractal boundary presents a higher influence on the velocity field and the resistance coefficient than other regular boundaries at the same Knudsen number and relative roughness. In addition, the effects of rarefaction, compressibility, and roughness are strongly coupled, and the roughness effect should not be ignored in studying rarefaction and compressibility of the microchannel as the relative roughness increases.

Lattice Boltzmann Simulation of Particle Motion in Binary Immiscible Fluids

2015 ◽  
Vol 18 (3) ◽  
pp. 757-786 ◽  
Author(s):  
Yu Chen ◽  
Qinjun Kang ◽  
Qingdong Cai ◽  
Moran Wang ◽  
Dongxiao Zhang
Keyword(s):  
Lattice Boltzmann ◽  
Particle Motion ◽  
Mass Conservation ◽  
Immiscible Fluids ◽  
Lattice Boltzmann Model ◽  
Lattice Boltzmann Simulation ◽  
Suspension Model ◽  
Wetting Model ◽  
Boltzmann Model ◽  
The Impact

AbstractWe combine the Shan-Chen multicomponent lattice Boltzmann model and the link-based bounce-back particle suspension model to simulate particle motion in binary immiscible fluids. The impact of the slightly mixing nature of the Shan-Chen model and the fluid density variations near the solid surface caused by the fluid-solid interaction, on the particle motion in binary fluids is comprehensively studied. Our simulations show that existing models suffer significant fluid mass drift as the particle moves across nodes, and the obtained particle trajectories deviate away from the correct ones. A modified wetting model is then proposed to reduce the non-physical effects, and its effectiveness is validated by comparison with existing wetting models. Furthermore, the first-order refill method for the newly created lattice node combined with the new wetting model significantly improves mass conservation and accuracy.

Lattice Boltzmann Simulation of Nucleation

2003 ◽  
Author(s):  
Takeshi Seta ◽  
Kenichi Okui ◽  
Eisyun Takegoshi
Keyword(s):  
Lattice Boltzmann ◽  
Lattice Boltzmann Model ◽  
Two Phase Flows ◽  
Two Phase ◽  
Lattice Boltzmann Simulation ◽  
Expansion Procedure ◽  
Theoretical Predictions ◽  
Boltzmann Method ◽  
Boltzmann Model ◽  
Pseudo Potential

We propose a lattice Boltzmann model capable of simulating nucleation. This LBM modifies a pseudo-potential so that it recovers a full set of hydrodynamic equations for two-phase flows based on the van der Waals-Cahn-Hilliard free energy theory through the Chapman-Enskog expansion procedure. Numerical measurements of thermal conductivity and of surface tension agree well with theoretical predictions. Simulations of phase transition, nucleation, pool boiling are carried out. They demonstrate that the model is applicable to two-phase flows with thermal effects. Using finite difference Lattice Boltzmann method ensures numerical stability of the scheme.

Lattice Boltzmann Simulation of Effect of Rolling Manipulation of Traditional Chinese Massage on Blood Flow

2013 ◽  
Vol 275-277 ◽  
pp. 472-477
Author(s):  
Hui Li Tan ◽  
Fan Rong Kong ◽  
Ke Zhao Bai ◽  
Ling Jiang Kong
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Flow Velocity ◽  
Lattice Boltzmann ◽  
Lattice Boltzmann Model ◽  
Lattice Boltzmann Simulation ◽  
Simulation Based ◽  
Wall Shear ◽  
Boltzmann Method ◽  
Boltzmann Model

A 2D Lattice Boltzmann model for a blood vesssel under rolling manipulation(RM) was presented. The influence of rolling frequency and stenosis coefficient on blood flux, wall shear stress and flow velocity was given by the numerical simulation based on lattice Boltzmann method . It is found that increasing RM frequency can not always increase the flux. There is a proper RM frequency for maximum flux.When the maximum stenosis coefficient increases,the change range of flux and wall shear stress will increase. The rolling massage can also change flow velocity in different sections of blood vessel.

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