保水堰堰井淹没出流时水体固有频率计算公式

Formula of Natural Frequency of Flow in Water-retaining Weir Well under Submerged Flow

为确定长距离分段低压输水系统中堰井淹没出流时水体的固有频率计算公式,基于带薄挡板矩形水箱水体固有频率计算公式,将原保水堰进行简化,并考虑堰厚及前后底板高差的影响,对水深进行修正,得到了保水堰堰井淹没出流时水体固有频率的计算公式,物理试验验证了修正公式具有较高的精度。利用Fluent软件模拟了不同堰高、堰厚、堰位置下水体的固有频率,发现修正公式计算结果比原公式更接近模拟值,进一步验证了修正公式的适用性,并给出了不同变量对固有频率的影响规律。

To give the formula of natural frequency of the flow in weir well of long-distance stepped low-pressure water supply system under submerged flow,based on the formula of natural frequency of the flow in rectangular tank with thin baffle,the original weir was simplified and the influence of its thickness and the height difference between fore-andaft floor were considered to revise the water depth value.The formula of natural frequency of the flow in weir well under submerged flow was obtained,which was verified that modified formula has high accuracy by comparison with the results of physical model test.The natural frequencies of flow under different weir heights,thicknesses and locations were simulated by Fluent software.Compared with the original formula,the modified formula was more consistent with the simulation results,which further verified the applicability of the modified formula.And the influence of these variables on the natural frequency is given.