大型拦污栅结构液固耦合流激振动分析

摘要

Flow-induced vibration and its influence factors were investigated for hydraulic trash-racks of the intake of Pakistan Jinnah Hydropower Station.The numerical analysis model was established,the fluid-structure interaction effect was investigated using element touchs between fluid and structure.The influence factors on dynamic characteristics of large trash-racks were analyzed including racks,fluid-structure interaction,brace constraint and boundary condition.The judgment conditions for vortex-resonance occurrence of large trash-racks were obtained.The results showed that the action of gird bars and the fluid-structure interaction have strong influences on the dynamic characteristics of a large trash-rack;reinforcing the structure may reduce its dynamic safety;while brace constraint and boundary condition have small effects on the trash-rack vibration.The study provided a new basis for evaluating the flow-induced vibration for this type trash-rack and a reference for revising the related technical standards.%以巴基斯坦真纳电站进水口拦污栅结构为对象，研究大型拦污栅结构流激振动及其影响因素。建立了拦污栅结构数值分析模型，以液固单元接触分析处理了液固耦合作用，分析了栅条作用、液固耦合、支撑约束及结构边界条件等因素对大型拦污栅结构动力特性的影响，给出了大型拦污栅避免栅体涡栅共振及栅条流激共振评判条件。结果表明：栅条作用与液固耦合对大型拦污栅结构动力特性的影响不容忽视，结构加固可能降低其动力安全性，而支撑约束及结构边界条件对拦污栅结构振动影响很小。该成果为该型拦污栅流激共振评判提供新依据，为相关技术标准修订提供参考。