用LDA测量U形水槽内的振荡流

本文介绍LDA用于测量U形水槽内的振荡流。水槽直管段为正方形,弯管段内侧弯面及外侧弯面是专门计算设计的。对于水平直管段、竖管段及弯管段共七个截面,测量了边界层外振荡流速的振幅分布。对于水平直管段上底面及下底面各三个截面,测量了边界层內振荡流速的振幅分布及相位分布。测量结果和无限长槽道的理论计算结果作了比较,二者基本符合。

MEASUREMENT OF THE OSCILLATORY FLOW IN AN U-TUBE WITH LDA

The oscillatory flow in an U-tube is measured using LDA. The horizontal section of the U-tube has a square cross-section. The shapes of the curved walls of the bent section are designed according to theoretical analysis. The velocity amplitude distributions of the oscillatory flow outside the boundary layer are measured at seven cross-sections along the horizontal, the vertical, and the bent sections respectively. Both the amplitude and the phase distributions of the oscillatory flow in the boundary layer are measured at three stations on the upper and the lower tube walls. Satisfactory agreements are obtained between the above measured results and thoce calculated from theory.