梯形透水潜坝附近水面线及透水率

Water surface profile and permeable rate near a trapezoidal permeable submerged dam

为研究结构物的透水特性和水动力特性,利用PIV流场测量系统专用水槽物理模型试验与Flow3D数值模拟相结合的方法研究均匀开孔的梯形透水潜坝附近水面线及坝体透水率的变化规律。结果表明:潜坝附近壅水及水跌高度随透空率的增大而减小,不同透空率潜坝坝后水面均出现"逆坡现象"。相同断面平均流速条件下,水深越大,相对壅水高度越小;当水深大于2倍坝高时,坝体壅水效果逐渐消失。相同坝前远端水深条件下,随着断面平均流速增大,坝后水跌高度增大。最后利用数模计算结果经回归拟合得到透水率的综合计算公式,经验证该经验公式计算结果和实测值最大偏差不超过5%,具有一定的可靠性。

To study the water-permeable characteristics and hydrodynamic characteristics of permeable structures,a specific physical flume model test with a PIV flow field measurement system combined with a Flow3D numerical simulation was used to study the water surface profile and permeable rate variation law of an open trapezoidal permeable submerged dam.The results show that the height of backwater and hydraulic drop near the submerged dam decreases with the increase of permeability,and a reverse slope phenomenon appears in the water surface behind the submerged dam with different permeability.Under the same cross-section average flow rate conditions,larger water depth corresponds to lower relative backwater height.When the water depth is greater than 2 times of the dam height,backwater gradually disappears.Under the condition of the same water depth in the far field in front of the dam,hydraulic drop height increases with the increase of cross-section average flow velocity.Finally,a comprehensive calculation formula of permeability is obtained by regression analysis of the numerical calculation results.It is proved that the maximum deviation between the empirical formula calculation results and the measured values is within 5%,showing a certain reliability.