水垫塘动水冲击压力测压管灵敏性分析

Sensitivity analysis of the piezometer under dynamic water impact pressure in cushion pools

随着一批高水头、大流量高拱坝的建设,水垫塘合理布置便成为工程设计中的一项重大技术问题,而动水冲击压力是水垫塘的一个重要指标。测压管法是目前水工模型试验中常用的较经济的方法。为了评价测压管测量水垫塘动水冲击压力的灵敏性,采用三维紊流数值模拟方法,对不同的测压孔内径和测压管内径比值下的水垫塘动水冲击压力测量敏感性进行分析,并用模型试验进行验证。研究结果表明:测压孔内径和测压管内径的比值对动水冲击压力测量有较大的影响,区别于常规水工模型试验要求(测压孔内径应小于2 mm,测压管内径宜大于6 mm);建议测压孔内径和测压管内径的比应大于0.7且测压管内径宜大于6 mm,并对冲击核心区域用脉动压力传感器法结合测量。

With the construction of a number of high-head,high-flow and high-arch dams,the reasonable design of plunge pools has become a major technical problem in engineering design,and the dynamic water impact pressure is an important indicator of the design of high dam cushion pools.The piezometer method is a more economical method commonly used in the current hydraulic model test.In order to evaluate the sensitivity of the piezometer to measure the dynamic water impact pressure,we used a three-dimensional turbulent flow numerical simulation method to analyze the effect of dynamic water impact pressure measurement in a cushion pool under different ratios of the inner diameter of the pressure tap to the inner diameter of the piezometer.The results show that the ratio of the inner diameter of the pressure tap to the inner diameter of the piezometer has a greater impact on the measurement of the dynamic water impact pressure,different from the conventional hydraulic model test requirements(the inner diameter of the pressure tap should be less than 2 mm,and the inner diameter of the piezometer should be greater than 6 mm).It is recommended that the ratio of the inner diameter of the pressure tap to the inner diameter of the piezometer should be greater than 0.7 and the inner diameter of the piezometer should be greater than 6 mm,and for the core area of the impact,the pulsation pressure sensor method should be combined with.