应用二维频移LDV测量多孔板管流的湍流特性

采用二维ＬＤＶ系统对圆管中装有四孔板和三孔板的湍流特性进行了实验研究．在孔板下游射流沿管轴逐渐混合．沿管壁可以观察到反向流区域．经足够长距离后，轴向和切向湍流度逐渐趋于相同数量级．实验结果表明，孔板结构和开孔度对湍流特性有重要影响．

Measurement of Turbulent Characteristics for the Pipe Flow from Perforated Plates by Using a 2D LDV System

The behavior of pipe flow emerging from a 4 hole or 3 hole perforated plated is investigated experimentally in a water circulating system by using a 2D frequency shifting LDV system. It is observed that the jets from the perforated plate mingle out gradually along the pipe axis, that a reverse flow region exists near the pipe wall and that beyond a sufficient distance from the perorated plate, the axial and the tangential turbulence intersities are reaching the same order. It is also found that the turbulent characteristics of the flow is strongly influenced by the porosity and configuration of the perforated plates.