反拱水垫塘拱圈底板动水压强时域与频域的变化规律

Variation pattern of hydrodynamic pressure on arched ring slabs in arch invert water-cushion pool in time and frequency domain

设计试验装置，测量高水头和大流量作用下反拱水垫塘全流场内拱圈底板动水压强．利用分析方法，得出拱圈底板表面与底板缝隙动水压强自相关特征和时空相关特征的变化规律，分析其与反拱水垫塘内水流的流动结构和流态之间的关系，揭示拱圈底板动水压强的变化和传播机理；对其频域特性进行分析，结果表明：拱圈底板表面动水压强的优势频率分布范围较广并比底板缝隙内的宽，其峰值频率分布范围主要集中在0～1Hz，脉动能量均以低频为主．

The experimental device was designed, and the hydrodynamic pressure on the arched-ring slabs in the arch invert water-cushion pool was measured in detail for the case of high water head and large discharge. Using the method of correlation analysis, the variation pattern of the characteristics of autocorrelation and time space correlation of hydrodynamic pressure on the arch ring slabs and in the slit of base slabs was obtained, its relations with flow structure and flow form in arch invert water-cushion pool were analyzed, and the change pattern and transmission mechanism of the hydrodynamic pressure on the ached base-slabs were revealed. It was found after analyzing the frequency domain characteristics that the hydrodynamic pressure on the inverted arch slab had a wider distribution range than that in the base slit, their range of peak value of frequencies being mainly focused on 0～1Hz and fluctuating energy being concentrated upon the range of low frequency.