桥墩冲刷坑的三维流场测量与数值模拟

Measurement and simulation of 3-D flow field in the pier scouring pool

采用Sontek公司声学多普勒测速仪(ADV)对有拦沙坝防护的模型桥墩附近流场进行了精细测量,对桥墩冲刷坑内三维流速分布进行了分析,给出了冲刷坑内三维紊动特征量的分布,分析研究了有拦沙防护坝时桥墩局部冲刷的三个新特点,提出了拦沙坝的适用条件。另外,还采用有限体积法(FCVM)对桥墩附近流场进行了三维水流数值模拟,与ADV实测数据进行了对比验证,结果比较吻合。利用测量与模拟成果分析了墩前三维流速分布规律及对桥墩局部冲刷的影响,对研究复杂边界桥墩流场结构与局部冲刷计算有参考价值。

In order to study local scouring field near the pier with sediment control dam, the 3-D velocity field of the pier in monomer model is subtly measured by ADV velocimeter of Sontek. This paper analyses the velocity distribution in the scouring pool of pier and takes turbulent strength distribution in different direction. Three new characters for the local scours of piers with the sediment control dam are analyzed and the dam＇s applicability is brought forward. The flow field near the pier is simulated by the 3-D mathematical model with FCVM, and the computing resuts have finer coherence compared with the measured value of ADV. The characteristic of the 3-D velocity distribution in front of piers and its influence on the local scour of the pier are studied in detail with the data from the measurement and simulation. It is very useful to analyze thoroughly the flow field structure of piers with the complex boundary and the local scouring theory.