Cros F, Flaud P, Dantan Ph
Laboratoire de Biorhéologie et d'Hémodynamique Physico-Chimique-CNRS ESA7057-Université PARIS VII, Denis DIDEROT LBHP-Tour 33/34-2 étage-case 7056 2, place Jussieu-75251 PARIS Cedex 05, France.
Comput Methods Biomech Biomed Engin. 2002 Dec;5(6):421-9. doi: 10.1080/1025584021000011109.
The venous network in the lower limbs is composed of a considerable number of confluent junctions. Each of these singularities introduces some blood flow disturbances. Each physiological junction is unique, in terms of its geometry as well as the blood flow rate. In order to account for this great variability, we developed a numerical model based on the use of the N3S code (a software package for solving Navier-Stokes equations). To test the validity of the model, one of the numerical simulations is compared with the data obtained in the corresponding experimental configuration. The velocity measurements were carried out with an ultrasonic pulsed Doppler velocimeter. We also measured pressure differences using differential sensors. The numerical computations were then used to obtain the values of the flow variables at any point, with various geometrical and flow configurations. As far as the velocity field is concerned, a very marked three-dimensional pattern with swirls was observed. The pressure evolution was also strongly disturbed, with a non-linear decrease. All these data indicate that confluence effects cannot be neglected when evaluating pressure decreases. With a tool of this kind, it is possible to accurately predict the disturbances associated with any geometrical configuration or any flow rate.
下肢静脉网络由大量汇合连接组成。这些独特之处中的每一个都会引入一些血流紊乱。每个生理连接在其几何形状以及血流速度方面都是独特的。为了考虑到这种巨大的变异性，我们基于使用N3S代码（一个用于求解纳维 - 斯托克斯方程的软件包）开发了一个数值模型。为了测试该模型的有效性，将其中一个数值模拟与在相应实验配置中获得的数据进行比较。速度测量是用超声脉冲多普勒测速仪进行的。我们还使用差动传感器测量了压力差。然后使用数值计算来获得在各种几何和流动配置下任意点处的流动变量值。就速度场而言，观察到了带有漩涡的非常明显的三维模式。压力演变也受到强烈干扰，呈非线性下降。所有这些数据表明，在评估压力降低时，汇合效应不能被忽略。使用这样一种工具，可以准确预测与任何几何配置或任何流速相关的干扰。
