平行平板流动腔脉动流切应力的计算

高度远小于横向和纵向几何尺寸的矩形平行平板流动腔是人们用以体外研究细胞在切应力作用下力学行为的主要工具之一。大多数研究者主要对定常层流情进行研究。本文通过对矩形平行平板流动腔内的层流脉动流进行详细分析，给出腔内速和腔室底部切应力的准确计算公式。当Ｗｏｍｅｒｓｌｅｙ数较小时，准确公式简化为准定常公式。数值计算结果表明，在脉动流条件下，对于人们常用的流动腔几何尺寸，准定常公式具有相当高的精度。这为在脉

Calculation of the Shear Stress in the Parallel- Plate Flow Chamber under Pulsatile Flow Condition

The parallel - plate flow chamber (PPFC) with rectangular shape, of which the height is far smaller than its own length and width, is one of the main apparatus for in vitro studies of the mechanical behavior of cultured endothe-lial cells undergoing shear stress. The PPFCs are usually utilized to study the cells' mechanical behavior under steady flow condition. The analysis of the pulsatile flow in PPFC is presented in detail in this study, and the precise formulas are derived to calculate the shear stress at the bottom of the chamber under general pulsatile flow conditions. For the pulsatile flow with small Womersley number, a quasi - steady flow expression for the calculation of the shear stress distribution is also presented. The calculated numerical results demonstrate that, the quasi - steady formula is highly precise for various commonly used flow parameters and geometrical dimensions of the PPFC, which provides theoretical basis for the calculation of the shear stress in the PPFC under pulsatile flow condition.