本文对不同Fr数的水跃底部脉动压力进行了试验测试,重点分析了水跃区底部脉动压力概率分布的正态性、最大幅值取值、脉动压力主频的沿程变化规律。结果表明:水跃跃首、跃尾脉动压力的概率分布接近正态分布,跃中强旋滚区偏离正态分布;最大振幅估计参数K(脉动压力均方根的倍数)在跃首、跃尾可取3,但在强旋滚区应取4~6;脉动压力主频沿程也有变化,跃首跃尾主频较低,旋滚区主频较高。
The fluctuating pressure distributions of hydraulic jump for various Froude numbers are measured in model test. The probability distribution characteristics, maximum amplitude and variation of master frequency along the longitudinal direction are analyzed. The result shows the probability distribution of fluctuating pressure at the front and terminal of hydraulic jump is approximately obeyed the law of normal distribution, whereas, the distribution deviates from normal distribution in the middle region of hydraulic jump in which strong eddies happened. The maximum amplitude is approximately equal to 3σ(square root of fluctuation amplitude) at the front and terminal and will be 4σ -6σ in strong eddy region. The master frequency at front and terminal is comparatively higher and is lower in strong eddy region.