摘要
进水口随机出现的漩涡转变为贯通性吸气漩涡时将对工程结构产生危害,但目前对这种随机出现的漩涡的研究很少。本文通过水槽试验,考虑来流边界的时均流速分布、紊动强度、水面波动强度以及进水口周边脉动压力等,对进水口随机出现的吸气漩涡的特征和影响因素进行研究。试验发现,进水口附近水面随机出现的吸气漩涡数量的历时过程具有和紊流相似的"拟序结构"特性。来流边界的水流紊动特性、水面波动以及进水口周边边界的壁压脉动等同步观测分析表明,来流边界的水流紊动显现的水面微波是进水口附近随机出现的漩涡的诱因。
The presence of stochastic vortex at an intake can reduce pumping efficiency,and in extreme cases,completely disable the intake.Despite the universal familiarity of this phenomenon,the existing literature provides little on the detailed mechanism of vortex formation.To study the mechanism and dynamics related,an experiment was conducted in a flume with a simulataneous observation of the vortex behavior and the inlet conditions,such as turbulent strength distribution,wave height and fluctuating pressure.The study found that the number of air-entraining vortices in the intake varies stochastically with time in a manner similar to the turbulent coherent structures.An analysis on the measured data indicates that the short-period waves on the free surface induced by flow turbulence are the major cause of the stochastic vortex near the intake.
出处
《水力发电学报》
EI
CSCD
北大核心
2009年第4期137-142,共6页
Journal of Hydroelectric Engineering
基金
国家自然科学基金项目(50579048)
关键词
水力学
随机出现漩涡
试验研究
拟序结构
hydraulics
stochastic vortex
experimental study
coherent structure
