静止浅水环境中二维铅垂掺气射流的试验研究

Experimental study on two-dimensional vertical bubble jets in static shallow water

对静止均匀浅水域中的铅垂掺气射流进行了试验研究 ,探讨了掺气浓度对水面最大隆起高度的影响 ;多种工况的研究成果表明水面隆起高度分布具有自相似性 ,并给出了统一的表达式 ;当掺气浓度小于 30 %时 ,最大隆起高度随着掺气量增加而增大 ,当大于 30 %时 ,其值基本趋于常数。借助于三维测速仪 ,得到了射流中心剖面的流场。与纯射流的流场对比表明 :水气两相流具有减小射流涡量的作用 ,有趣地发现 。

This paper presents an experimental study of two dimensional bubble jets discharged vertically through a rectangle submerged pipe into a large of stagnant non stratified water of finite depth. The bubble jets were formed with a gas water mixer. The experiments were carried out in laboratory facilities consisting of a closed system capable of maintaining steady state conditions. The relation between the maximum water surface elevation and air concentration was obtained. The self similarity of the distribution of water surface elevation were found and the corresponding formula was given. The information of bubble jets was obtained by micro ADV system. The comparison between pure jets and bubble jets show that the water gas two phase flow has the effect of reducing vorticity. It is found that there is a vortex street alternatively with positive and negative shrengths along jet centerline.