This paper characterizes the hydrodynamics of laminar flows through circular ducts equipped with plain square woven meshes/screens in their role as static mixers. The CFD model was used to investigate the effect of screen geometry, number of screens, inter-screen spacing, and operating conditions on the velocity and pressure fields. This work therefore presents an analysis of the velocity contours, streamlines, and profiles at various locations within the pipe in addition to the pressure profiles to obtain a better understanding of the complex behavior of the flow.

The presence of screens normal to the flow was found to alter the fully developed parabolic profile and flatten it both upstream and downstream, hence simultaneously decelerating and accelerating regions in the cross-sectional area of the flow. Downstream of screens, the velocity profile was characterized by a sinusoidal shape that quickly decays, and vortices were observed under certain operating and design conditions.

The study of the pressure field helped delineate the contribution of static and dynamic pressures in addition to identifying a minimum inter-screen distance if maximum pressure recovery is desired. Predictions of the pressure drop for various mesh geometries and under different operating conditions were validated using empirical correlations and the results reflected a very good accuracy with the maximum relative error falling within $\pm$ 7.3%.

本文描述了通过圆形管道的层流的流体动力学特性，该圆形管道配备有纯正方形编织网/筛网，并充当静态混合器。CFD模型用于研究筛网几何形状，筛网数量，筛网间距以及操作条件对速度和压力场的影响。因此，这项工作除了对压力分布图进行分析外，还对管道内各个位置的速度分布图，流线图和分布图进行了分析，以便更好地了解流的复杂行为。

发现垂直于流的滤网的存在改变了完全展开的抛物线轮廓并使它在上游和下游均变平，因此同时使流的横截面区域减速和加速。在滤网的下游，速度分布的特征是正弦曲线形状会迅速衰减，并且在某些操作和设计条件下会观察到涡旋。

压力场的研究有助于确定静态和动态压力的作用，此外，如果需要最大的压力恢复能力，则还可以确定最小的筛间距离。使用经验相关性验证了各种网格几何形状和在不同操作条件下的压降预测，结果反映出非常好的精度，最大相对误差在$\pm$ 7.3％。