水垫塘冲击射流附壁区的水力特性

Hydraulic Characteristics of the Wall-jet Region in a Pool with an Oblique Submerged Jet

采用粒子成像测速技术(PIV)获得了水垫塘冲击射流全域瞬时精细流场,并在此基础上,对附壁射流区的流速分布规律和水流紊动特征等水力特性进行了系统研究。结果表明:在附壁射流区,射流横向断面的流速、紊动强度分布呈自相似分布规律,具有自由射流的特征;在射流纵向,流速随着流程增加而线性减小,射流半扩展厚度和紊动强度随流程增加而线性增大;并提出了描述附壁射流区射流横向断面流速、紊动强度分布规律的方程,同时得到了附壁射流区射流纵向上流速、半扩展厚度和紊动强度沿流程变化的计算公式。

The particle image velocimetry( PIV) was used to characterize the fine structure of flow fields in a pool with an oblique submerged jet,and on this basis,the jet velocity distribution and turbulence characteristics in the wall-jet region were studied systemically.The results showed that in the wall-jet region,the velocity and turbulence intensity distribution in each of the jet flow cross-sections are the self-similarity,which is the same as that of a free jet. In the wall-jet region,the jet velocity decreases linearly along the jet path,whereas the turbulence intensity,the jet half-width increases linearly as the jet travels. The equations of jet velocity and turbulent intensity distributions were proposed,and the formulas to calculate the jet velocity,the turbulence intensity,the jet half-width changing along the jet path were also obtained.