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Non-Newtonian Effect on Hemodynamic Characteristics of Blood Flow in Stented Cerebral Aneurysm

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Communications in Computational Physics 2013年第3期13卷 916-928页

作者： Changsheng Huang zhenhua chai Baochang Shi School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074P.R.China

Stent placement is considered as a promising and minimally invasive technique to prevent rupture of aneurysm and favor coagulation mechanism inside the *** scholars study the effect of the stent on blood flow in cerebral aneurysm by numerical simulations,and usually regard blood as the Newtonian fluid,blood,however,is a kind of non-Newtonian fluid in *** main purpose of the present paper is to investigate the effect of non-Newtonian behavior on the hemodynamic characteristics of blood flow in stented cerebral aneurysm with lattice Boltzmann *** Casson model is used to describe the blood non-Newtonian character,which is one of the most popular models in depicting blood *** particular,hemodynamic characteristics derived with Newtonian and non-Newtonian models are studied,and compared in *** results show that the non-Newtonian effect gives a great influence on hemodynamic characteristics of blood flow in stented cerebral aneurysm,especially in small necked ones.

关键词： Cerebral aneurysm lattice Boltzmann non-Newtonian fluid Casson model

Gas Flow Through Square Arrays of Circular Cylinders with Klinkenberg Effect:A Lattice Boltzmann Study

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Communications in Computational Physics 2010年第10期8卷 1052-1073页

作者： zhenhua chai Baochang Shi Zhaoli Guo Jianhua Lu School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan430074China

It is well known that,as non-continuum gas flows through microscale porous media,the gas permeability derived from Darcy law is larger than the absolute permeability,which is caused by the so-called Klinkenberg effect or slippage *** this paper,an effective definition of Knudsen number for gas flows through square arrays of circular cylinders and a local boundary condition for non-continuum gas flows are first proposed,and then the multi-relaxation-time lattice Boltzmann equation including discrete effects on boundary condition is used to investigate Klinkenberg effect on gas flow through circular cylinders in square *** results show that the celebrated Klinkenberg equation is only correct for low Knudsen number,and secondorder correction to Klinkenberg equation is necessary with the increase of Knudsen ***,the present numerical results are also compared to some available results,and in general an agreement between them is observed.

关键词： Klinkenberg effect multi-relaxation-time lattice Boltzmann equation Knudsen number Klinkenberg equation

Lattice BGK Model for Incompressible Axisymmetric Flows

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Communications in Computational Physics 2012年第5期11卷 1569-1590页

作者： Ting Zhang Baochang Shi zhenhua chai Fumei Rong State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan 430074China School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074China

In this paper,a lattice Boltzmann BGK(LBGK)model is proposed for simulating incompressible axisymmetric *** other existing axisymmetric lattice Boltzmann models,the present LBGK model can eliminate the compressible effects only with the smallMach number *** the source terms of themodel are simple and contain no velocity *** the Chapman-Enskog expansion,the macroscopic equations for incompressible axisymmetric flows can be exactly recovered fromthe present *** simulations of theHagen-Poiseuille flow,the pulsatile Womersley flow,the flow over a sphere,and the swirling flow in a closed cylindrical cavity are *** results agree well with the analytic solutions and the existing numerical or experimental data reported in some previous studies.

关键词： Lattice BGK model incompressible axisymmetric

Numerical Study on the Tortuosity of Porous Media via Lattice Boltzmann Method

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Communications in Computational Physics 2009年第7期6卷 354-366页

作者： Jianhua Lu Zhaoli Guo zhenhua chai Baochang Shi State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan430074China School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan430074China

In this paper,we simulate the pressure driven fluid flow at the pore scale level through 2-D porous media,which is composed of different curved channels via the lattice Boltzmann *** this direct simulation,the relation between the tortuosity and the permeability is *** numerical results are in good agreement with the existing theory.

关键词： Tortuosity lattice Boltzmann porous media pore scale

Simulation of Power-Law Fluid Flows in Two-Dimensional Square Cavity Using Multi-Relaxation-Time Lattice Boltzmann Method

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Communications in Computational Physics 2014年第1期15卷 265-284页

作者： Qiuxiang Li Ning Hong Baochang Shi zhenhua chai State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan430074P.R.China. Department of Foundational Courses Jiangcheng CollegeChina University of GeosciencesWuhan430200P.R.China. School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan430074P.R.China.

In this paper,the power-law fluid flows in a two-dimensional square cavity are investigated in detail with multi-relaxation-time lattice Boltzmann method(MRTLBM).The influence of the Reynolds number(Re)and the power-law index(n)on the vortex strength,vortex position and velocity distribution are extensively *** our numerical simulations,Re is varied from 100 to 10000,and n is ranged from 0.25 to 1.75,covering both cases of shear-thinning and *** with the Newtonian fluid,numerical results show that the flow structure and number of vortex of power-law fluid are not only dependent on the Reynolds number,but also related to power-law index.

关键词： Multi-relaxation-time lattice Boltzmann method power-law fluid shear-thinning shear-thickening.

Implementation of Multi-GPU Based Lattice Boltzmann Method for Flow Through Porous Media

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Advances in Applied Mathematics and Mechanics 2015年第1期7卷 1-12页

作者： Changsheng Huang Baochang Shi Nanzhong He zhenhua chai School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074China

The lattice Boltzmann method(LBM)can gain a great amount of performance benefit by taking advantage of graphics processing unit(GPU)computing,and thus,the GPU,ormulti-GPU based LBMcan be considered as a promising and competent candidate in the study of large-scale fluid ***,the multi-GPU based lattice Boltzmann algorithm has not been studied extensively,especially for simulations of flow in complex *** this paper,through coupling with the message passing interface(MPI)technique,we present an implementation of multi-GPU based LBM for fluid flow through porous media as well as some optimization strategies based on the data structure and layout,which can apparently reduce memory access and completely hide the communication time *** the performance of the algorithm is tested on a one-node cluster equipped with four Tesla C1060 GPU cards where up to 1732 MFLUPS is achieved for the Poiseuille flow and a nearly linear speedup with the number of GPUs is also observed.

关键词： Lattice Boltzmann method GPU computing CUDA porous media MPI

Lattice Boltzmann Study of Flow and Temperature Structures of Non-Isothermal Laminar Impinging Streams

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Communications in Computational Physics 2013年第3期13卷 835-850页

作者： Wenhuan Zhang zhenhua chai Zhaoli Guo Baochang Shi State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan 430074China School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074China

Previous works on impinging streams mainly focused on the structures of flow field,but paid less attention to the structures of temperature field,which are very important in practical *** this paper,the influences of the Reynolds number(Re)and Prandtl number(Pr)on the structures of flow and temperature fields of non-isothermal laminar impinging streams are both studied numerically with the lattice Boltzmann method,and two cases with and without buoyancy effect are *** results show that the structures are quite different in these ***,in the case with buoyancy effect,some new deflection and periodic structures are found,and their independence on the outlet boundary condition is also *** findings may help to understand the flow and temperature structures of non-isothermal impinging streams further.

关键词： Impinging streams lattice Boltzmann method flow structure temperature structure

A Pseudopotential Lattice Boltzmann Analysis for Multicomponent Flow

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Communications in Computational Physics 2022年第9期32卷 1156-1178页

作者： Yong Zhao Gerald G.Pereira Shibo Kuang zhenhua chai Baochang Shi School of Mathematics and Statistics Changsha University of Science and TechnologyChangsha 410114HunanChina CSIRO Data61 Private Bag 10Clayton South 3168Australia ARC Research Hub for Computational Particle Technology Department of Chemical EngineeringMonash UniversityVictoria 3800Australia School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074China

This paper presents a pseudopotential lattice Boltzmann analysis to show the deficiency of previous pseudopotential models,i.e.,inconsistency between equilibrium velocity and mixture *** rectify this problem,there are two strategies:decoupling relaxation time and kinematic viscosity or introducing a system mixture relaxation ***,we constructed two modified models:a two-relaxationtime(TRT)scheme and a triple-relaxation-time(TriRT)scheme to decouple the relaxation time and kinematic ***,inspired by the idea of a system mixture relaxation time,we developed three mixture models under different collision schemes,***-SRT,mix-TRT,and mix-TriRT ***,we derived the advection-diffusion equation for the multicomponent system and derived the mutual diffusivity in a ***,we conducted several numerical simulations to validate the analysis on these *** numerical results show that these models can obtain smaller spurious currents than previous models and have a wider range for the accessible viscosity ratio with fourth-order *** to previous models,presentmodels avoid complex matrix operations and only fourth-order isotropy is *** increased simplicity and higher computational efficiency of these models make them easy to apply to engineering and industrial applications.

关键词： Lattice Boltzmann method multicomponent flows Chapman-Enskog analysis

A Diffuse-Interface Lattice Boltzmann Method for the Dendritic Growth with Thermosolutal Convection

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Communications in Computational Physics 2023年第4期33卷 1164-1188页

作者： Chengjie Zhan zhenhua chai Baochang Shi Ping Jiang Shaoning Geng Dongke Sun School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan430074P.R.China Institute of Interdisciplinary Research for Mathematics and Applied Science Huazhong University of Science and TechnologyWuhan 430074P.R.China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and TechnologyWuhan430074P.R.China The State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074P.R.China School of Mechanical Engineering Southeast UniversityNanjing 211189P.R.China

In this work,we proposed a diffuse-interface model for the dendritic growth with thermosolutal *** this model,the sharp boundary between the fluid and solid dendrite is firstly replaced by a thin but nonzero thickness diffuse interface,which is described by the order parameter,and the diffuse-interface based governing equations for the dendritic growth are *** solve the model for the dendritic growth with thermosolutal convection,we also developed a diffuse-interface multirelaxation-time lattice Boltzmann(LB)*** this method,the order parameter in the phase-field equation is combined into the force caused by the fluid-solid interaction,and the treatment on the complex fluid-solid interface can be *** addition,four LB models are designed for the phase-field equation,concentration equation,temperature equation and the Navier-Stokes equations in a unified ***,we performed some simulations of the dendritic growth to test the present diffuse-interface LB method,and found that the numerical results are in good agreements with some previous works.

关键词： Dendritic growth diffuse interface lattice Boltzmann method phase-field method.