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Simulation of Blood Flow at Vessel Bifurcation by Lattice Boltzmann Method 总被引:1,自引:0,他引:1 下载免费PDF全文
The application of the lattice Boltzmann method to the large vessel bifurcation blood flow is investigated in a wide range of Reynolds numbers. The velocity, shear stress and pressure distributions at the bifurcation are presented in detail The flow separation zones revealed with increase of Reynolds number are located in the areas of the daughter branches distal to the outer corners of the bifurcation where some deposition of particular blood components might occur to form arteriosclerosis. The results also demonstrate that the lattice Boltzmann method is adaptive to simulating the flow in larger vessels under a high Reynolds number. 相似文献
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The multi-bifurcation effect of blood flow is investigated by lattice Boltzmann method at Re=200 with six different bifurcation angles α, which are 22.5°, 25°, 28°, 30°, 33°, 35°, respectively. The velocities and ratios of average velocity at various bifurcations are discussed. It is indicated that the maximum velocity at the section near the first divider increases and shifts towards the walls of branch with the increase of α. At the first bifurcation, the average horizontal velocities increase with the increase of α. The average horizontal velocities of outer branches at the secondary bifurcation decrease at 22.5°≤ α≤30° and increase at 30°≤α≤ 35°, whereas those of inner branches at the secondary bifurcation have the opposite variation, as the same as the above variations of the ratios of average horizontal velocities at various bifurcations. The ratios of average vertical velocities of branch at first bifurcation to that of outer branches at the secondary bifurcation increase at 22.5°≤α≤30° and decrease at 30°≤ α ≤ 35°, whereas the ratios of average vertical velocities of branch at first bifurcation to that of inner branches at the secondary bifurcation always decrease. 相似文献
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SHI Juan QIU Bing TAN Hui-Li 《理论物理通讯》2009,51(6):1117-1120
A lattice Boltzmann model is presented to simulate the deformation and motions of a red blood cell (RBC) in a shear flow. The curvatures of the membrane of a static RBC with different chemical potential drops calculated by our model agree with those computed by a shooting method very well. Our simulation results show that in a shear flow, a biconcave RBC becomes highly flattened and undergoes tank-treading motion. With intrinsically parallel dynamics, this lattice Boltzmann method is expected to find wide applications to both single and multi-vesicles suspension as well as complex open membranes in various fluid flows for a wide range of Reynolds numbers. 相似文献
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The rolling massage manipulation is a classic Chinese massage, which is expected to improve the circulation by pushing, pulling and kneading of the muscle. A model for the rolling massage manipulation is proposed and the lattice Boltzmann method is applied to study the blood flow in the blood vessels. The simulation results show that the blood flux is considerably modified by the rolling massage and the explicit value depends on the rolling frequency, the rolling depth, and the diameter of the vessel. The smaller the diameter of the blood vessel, the larger the enhancement of the blood flux by the rolling massage. The model, together with the simulation results, is expected to be helpful to understand the mechanism and further development of rolling massage techniques. 相似文献
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基于D1Q4可压缩格子Boltzmann模型,按照流通矢量分裂方法的思路,采用坐标旋转技术构造求解三维带化学反应Navier-Stokes方程对流通量求解器.结合有限体积法求解三维化学非平衡流Navier-Stokes方程,采用时间算子分裂算法解决化学反应刚性问题,数值模拟超声速化学非平衡流的三个经典算例.数值结果表明:在高马赫数下,采用D1Q4可压缩格子Boltzmann模型构造的三维对流通量求解器数值模拟中没有出现非物理解,同时在超声速化学非平衡流场中正确分辨激波、燃烧波等物理现象,精度和分辨率均较高,验证了本文构造的三维对流通量求解器的可靠性,拓宽了D1Q4可压缩格子Boltzmann模型的应用范围,为计算超声速化学非平衡流提供一种新方法. 相似文献
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Blood flow under various conditions of vessel is simulated as a non-Newtonian fluid by the two-dimensional Lattice Boltzmann method, in which the Casson model is used to express the relationship between viscosity and shear rate of the blood. The flow field distributions at certain sites near the narrowing and bifurcation of the vessel explain the hemodynamic mechanism of the predilection of the atherosclerotic lesions for these sites which are consistent with that found by medical studies. 相似文献
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Y. H. Zhang R. S. Qin Y. H. Sun R. W. Barber D. R. Emerson 《Journal of statistical physics》2005,121(1-2):257-267
Gas flow in microchannels can often encounter tangential slip motion at the solid surface even under creeping flow conditions.
To simulate low speed gas flows with Knudsen numbers extending into the transition regime, alternative methods to both the
Navier–Stokes and direct simulation Monte Carlo approaches are needed that balance computational efficiency and simulation
accuracy. The lattice Boltzmann method offers an approach that is particularly suitable for mesoscopic simulation where details
of the molecular motion are not required. In this paper, the lattice Boltzmann method has been applied to gas flows with finite
Knudsen number and the tangential momentum accommodation coefficient has been implemented to describe the gas-surface interactions.
For fully-developed channel flows, the results of the present method are in excellent agreement with the analytical slip-flow
solution of the Navier–Stokes equations, which are valid for Knudsen numbers less than 0.1. The present paper demonstrates
that the lattice Boltzmann approach is a promising alternative simulation tool for the design of microfluidic devices. 相似文献
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The numerical simulation of thrombosis in stented aneurysms is an important issue to estimate the efficiency of a stent. In
this paper, we consider a Lattice Boltzmann (LB) approach to bloodflow modeling and we implement a non-Newtonian correction
in order to reproduce more realistic flow profiles. We obtain a good agreement between simulations and Casson’s model of blood
rheology in a simple geometry. Finally we discuss how, by using a passive scalar suspension model with aggregation on top
of the LB dynamics, we can describe the clotting processes in the aneurysm 相似文献
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分析格子Boltzmann方法中二阶精度的曲线边界处理方法.应用格子Boltzmann方法及其边界处理方法模拟1/4圆腔内的定常层流运动,引入流线图和等涡线图分析流场随Re数的变化.并且发现当Re数在10~100区间内变化时,随着Re数的增大,顺时针旋转流场的涡心位置偏离x轴的角度逐渐减小,而逆时针旋转流场的涡心位置偏离x轴的角度却越来越大. 相似文献
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Zhengdao Wang Xiandong Zhang Yumeng Li Hui Yang Haihong Xue Yikun Wei Yuehong Qian 《Entropy (Basel, Switzerland)》2022,24(2)
In this paper, the lattice Boltzmann method was used to simulate the cardiac flow in children with aseptal defect. The inner wall model of the heart was reconstructed from 210 computed tomography scans. By simulating and comparing the cardiac flow field, the pressure field, the blood oxygen content, and the distribution of entropy generation before and after an operation, the effects of septal defect on pulmonary hypertension(PH), cyanosis, and heart load were analyzed in detail. It is found that the atrial septal defect(ASD) of the child we analyzed had a great influence on the blood oxygen content in the pulmonary artery, which leads to lower efficiency of oxygen binding in the lungs and increases the burden on the heart. At the same time, it also significantly enhanced the entropy generation rate of the cardiac flow, which also leads to a higher heart load. However, the main cause of PH is not ASD, but ventricular septal defect (VSD). Meanwhile, it significantly reduced the blood oxygen content in the brachiocephalic trunk, but rarely affects the blood oxygen contents in the downstream left common carotid artery, left subclavian artery, and descending aorta are not significantly affected by VSD. It causes severe cyanosis on the face and lips. 相似文献
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Changsheng Huang Baochang Shi Nanzhong He & Zhenhua Chai 《advances in applied mathematics and mechanics.》2015,7(1):1-12
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, or multi-GPU based LBM can be
considered as a promising and competent candidate in the study of
large-scale fluid flows. However, the multi-GPU based lattice
Boltzmann algorithm has not been studied extensively, especially for
simulations of flow in complex geometries. In 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 consumption. Then
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. 相似文献
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The lattice Boltzmann equation (LBE) is considered as a promising approach
for simulating flows of liquid and gas. Most of LBE studies have been devoted to regular
square LBE and few works have focused on the rectangular LBE in the simulation
of gaseous microscale flows. In fact, the rectangular LBE, as an alternative and efficient
method, has some advantages over the square LBE in simulating flows with certain
computational domains of large aspect ratio (e.g., long micro channels). Therefore,
in this paper we expand the application scopes of the rectangular LBE to gaseous microscale
flow. The kinetic boundary conditions for the rectangular LBE with a multiple-relaxation-time
(MRT) collision operator, i.e., the combined bounce-back/specular-reflection
(CBBSR) boundary condition and the discrete Maxwell's diffuse-reflection
(DMDR) boundary condition, are studied in detail. We observe some discrete effects
in both the CBBSR and DMDR boundary conditions for the rectangular LBE and
present a reasonable approach to overcome these discrete effects in the two boundary
conditions. It is found that the DMDR boundary condition for the square MRT-LBE
can not realize the real fully diffusive boundary condition, while the DMDR boundary
condition for the rectangular MRT-LBE with the grid aspect ratio a≠1 can do it well.
Some numerical tests are implemented to validate the presented theoretical analysis.
In addition, the computational efficiency and relative difference between the rectangular
LBE and the square LBE are analyzed in detail. The rectangular LBE is found to be
an efficient method for simulating the gaseous microscale flows in domains with large
aspect ratios. 相似文献