Model studies of leukocyte-endothelium-blood interactions
Model studies of leukocyte-endothelium-blood interactions
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DOI：
10.1016/s0006-355x(97)00003-6
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发表时间：
1997-01-01
期刊：
影响因子：
1.1
通讯作者：
Cokelet, GR
中科院分区：
文献类型：
--
作者：
Chapman, GB;Cokelet, GR
应用计算流体力学（CFD）和大尺度模型实验分析了白细胞粘附于毛细血管后微静脉壁对血液动力学的影响。使用一个大规模的模型，并与有限元软件包的帮助下，求解Navier Stokes方程的低雷诺数流动在一个圆柱体过去的粘附球，我们已经开发出一个无量纲的相关性，允许估计的压降在体内血管中的粘附白细胞。这种关系是：F。Re = exp[ 2.877 + 4.630（d/D）（4）]式中，f为范宁摩擦系数，Re为雷诺数，d/D为白细胞与血管直径比。摩擦系数与穿过白细胞的压降成比例，并且直到d/D大于0.5才显著增加，然后随着d/D的增加而迅速增加。计算表明，粘附白细胞产生的扰动流区的长度随着血管尺寸的减小而增加。在扰动流区的平均壁应力保持恒定，并且当d/D小于约0.5时等于未扰动区的壁应力。当d/D大于0.5时，扰动流区的平均壁面应力随d/D的增大而迅速增大。在扰动区域中的峰值壁应力中存在甚至更大的增加，高达平均扰动应力的五倍。这表明在毛细血管后尺寸的血管中粘附的白细胞可以产生显著的壁应力梯度。(C)1997年爱思唯尔科学有限公司
Computational fluid dynamics (CFD) and large scale model experiments were used to analyze the hemodynamic impact of leukocytes adherent to the wall of post-capillary venules. Using a large scale model and, with the aid of a finite element package, solving the Navier Stokes equations for low Reynolds number flow in a cylinder past an adherent sphere, we have developed a dimensionless correlation which permits the estimation of the pressure drop across an adherent leukocyte in an in vivo vessel. This relationship is:f . Re = exp[ 2.877 + 4.630(d/D)(4)]where fis the Fanning friction factor, Re is the Reynolds number and d/D is the leukocyte to vessel diameter ratio. The friction factor is proportional to the pressure drop across the leukocyte, and does not significantly increase until d/D is greater than 0.5, and then increases rapidly with increasing d/D. Computations indicate that the length of the disturbed flow region generated by an adherent leukocyte increases with decreasing vessel size, The average wall stress in the disturbed flow region remains constant, and equal to the wall stress in the undisturbed region for d/D less than approximately 0.5. For d/D greater than 0.5, the average wall stress in the disturbed flow region increases rapidly with increasing d/D. There is an even larger increase, up to five times greater than the average disturbed stress, in the peak wall stress in the disturbed now region, This indicates that significant wall stress gradients can be generated by an adherent leukocyte in post-capillary size vessels. (C) 1997 Elsevier Science Ltd.