Barr D W
Barr Engineering Co., 4700 West 77th St., Minneapolis, MN 55435, USA.
Ground Water. 2001 Sep-Oct;39(5):646-50. doi: 10.1111/j.1745-6584.2001.tb02353.x.
The pressure driving flow through porous media must be equal to the viscous resistance plus the inertial resistance. Formulas are developed for both the viscous resistance and the inertial resistance. The expression for the coefficient of permeability consists of parameters which describe the characteristics of the porous medium and the permeating fluid and which, for unconsolidated isotropic granular media, are all measurable. A procedure is proposed for testing for the occurrence of turbulence and calculating the effective permeability when it occurs. The formulas are applied to a set of data from 588 permeameter runs ranging from laminar to highly turbulent. The equations fit the data from the permeameter closely through the laminar flow conditions and quite closely through the turbulent conditions. In the turbulent range, the plotting of the data separates into three distinct lines for each of the three shapes of particles used in the tests. For the porous medium and fluid of these tests, turbulence begins at a head gradient of about 0.1.
驱动流体通过多孔介质的压力必须等于粘性阻力加上惯性阻力。文中推导了粘性阻力和惯性阻力的公式。渗透率系数的表达式由描述多孔介质和渗透流体特性的参数组成，对于未固结的各向同性颗粒介质，这些参数都是可测量的。文中提出了一种测试湍流是否发生以及在湍流发生时计算有效渗透率的方法。这些公式应用于588次渗透仪试验的数据，试验范围从层流到高度湍流。这些方程在层流条件下能很好地拟合渗透仪数据，在湍流条件下也拟合得相当好。在湍流范围内，对于试验中使用的三种颗粒形状，数据绘制可分为三条不同的线。对于这些试验中的多孔介质和流体，湍流在水头梯度约为0.1时开始。
