射流冲击水垫塘入射点旋涡掺气特性的研究

通过实验研究了不掺气射流冲击水垫塘入射点旋涡掺气的特性。实验结果表明：空气从射流入射点被卷入后，沿射流剪切层扩散；入射点掺气浓度随水垫深度的减小而增加；剪切层内水气混合体的流速分布具有误差函数形式；在剪切层内、外区，其掺气浓度分别符合高斯分布，与理论计算吻合良好。另外，还从理论上导出了射流入射点附近水气混合层的厚度，并给出了计算掺气量的公式。

BEHAVIOUR OF AIR ENTRAINED BY ROLLERS AT THE POINT IF NON-AERATED PLUNGING JET ENTRY

This paper investigates behaviour of air ent rained by rollers at the point ofnon-aerated plunging jet entry. Experimental results indicate that air retained from thepoint of jet entry diffuses along shear layer.Air concentration at the point of entry increocseswith water depth decreasing.There is a form of error function for velocity distribution ofair-water mixture in shear laver. Air concentration is correspondent to normal distribution,in internal and external shear layers respectively. The agreement between the theoreticalequations and the experimental results is good.In addition,the thickness of air-water mixinglayer and air flow rate near the point of jet entry are given theoretically.