EXPERIMENTAL STUDIES ON FREQUENCY CHARACTERISTICS OF THE FLUCTUATING PRESSURE ACTING ON THE APRON OF STILLING BASINS WITH LOW FROUDE NUMBER

Using four types of stilling basin models,this paper studies frequency characteris-tics of the fluctuating pressure acting on the stilling basin apron when Froude number is notgreater than 4.5.The testing results show that the frequency of fluctuating pressure,fin theranges of 0. 4Hz≤f≤1.1Hz.0.2Hz≤f≤2.5Hz and 0.4Hz≤f≤3.3Hz.can be used as thedesign frequency corresponding to three patterns of hydraulic jump.The reliability of ffor threejump patterns is all nearly equal to 90%.