摘要
为了获取贯流泵固定导叶的应力应变和振动特性,基于单向流固耦合法,开展多流量工况下后置灯泡贯流泵固定导叶应力应变和湿模态分析。结果表明:随着流量的增加,导叶片表面最大等效应力和应变量整体趋于减小;小流量和设计流量工况下,导叶片表面的等效应力和应变分布相似;大流量工况下,等效应力沿水泵导叶根部分布,占整个吸力面达90%,较大的应变则出现在导叶片外缘的中上部,变形区域约占整个导叶的60%;导叶固有频率与流量工况关联性不大,其值随着模态振型的阶数增加而增加,共振风险分析中可以忽略流量因素的影响。研究成果对贯流泵固定导叶优化及运行稳定性的提高有一定借鉴意义。
A pump is a device that can convert mechanical energy into liquid kinetic energy and achieve directional liquid transportation,and has been widely used in many fields.The tubular pump is widely used in low-lift pumping stations due to its high efficiency,good hydraulic performance,and compact structure.Compared with the axial flow pump and the mixed flow pump unit,under the same excavation conditions,the tubular pump unit can reduce the amount of plant excavation and the amount of concrete used,which greatly reduces the overall cost of the pumping station.Because the unit is horizontally arranged,the flow conditions are good,and the hydraulic loss is small.Compared with the vertical unit,the tubular pump plant has a simple structure and does not need to use a complex multi-layer structure,which reduces the overall cost.It is widely used in plain areas.In recent years,many scholars at home and abroad have conducted researches on the internal flow of tubular pumps.With the development of computer technology,the computational fluid dynamics(CFD)and computational solid mechanics(CSM)combined fluid-solid coupling calculation method has the advantages of short time-consuming,low cost,and easy access to flow data and solid data in the flow field.It is mostly used to calculate the interaction between fluid and solid inside fluid machinery.To obtain the stress,strain,and vibration characteristics of the fixed guide vane of the tubular pump,based on the unidirectional fluid-structure coupling method,the stress,strain,and wet modal analysis of the fixed guide vane of the rear bulb tubular pump under multi-flow conditions were carried out.The results show that with the increase in flow,the maximum equivalent stress and strain on the surface of the guide vane tend to decrease as a whole.The distribution of equivalent stress and strain on the surface of the guide vane is similar under low flow and design flow conditions.Under large flow conditions,the equivalent stress is distributed along the root of the guide vane of the water pump,accounting for 90%of the entire suction surface,and the larger strain appears in the middle and upper part of the outer edge of the guide vane,and the deformation area accounts for about 60%of the entire guide vane.The natural frequency of the guide vane has little relevance to the flow conditions,and its value increases with the increase of the order of the mode shape.The influence of flow factors can be ignored in the resonance risk analysis.(1)As the flow rate increases,the equivalent stress and strain on the surface of the guide vane tend to decrease.(2)The equivalent stress distribution area of the pressure surface of the guide vane under the design flow and the small flow condition is the same.It is located at the root and the middle of the outer edge of the inlet and outlet of the guide vane.Its size accounts for about 40%of the guide vane.The situation is quite different,from the inlet and outlet roots of the guide vane to the middle,and its size accounts for about 90%of the guide vane.It is recommended to pay attention to the equivalent stress at the root of the guide vane when designing the guide vane of the tubular pump.(3)Under different flow conditions,the strain distribution between the guide vanes is significantly different.The large strain area of each blade is mainly concentrated on the outer edge of the guide vane,and there is no obvious strain at the root of the guide vane.It is suggested that when designing the guide vane of the tubular pump,the strain change of the outer edge of the guide vane should be paid attention.(4)By analyzing the calculation results of the first ten wet modes of the guide vane,it is found that the vibration frequency of each order of the guide vane is not highly correlated with the flow factor.The value of the vibration frequency of the guide vane will increase with the increase of the order,but the increase is not large.Therefore,the resonance risk analysis can ignore the influence of flow changes on its vibration frequency.
作者
施伟
李加旭
李松柏
孙涛
范雪梅
成立
罗灿
SHI Wei;LI Jiaxu;LI Songbai;SUN Tao;FAN Xuemei;CHENG Li;LUO Can(The Eastern Route of South-to-North Water Diversion Project Jiangsu Water Source Co.,Ltd.Naning 210029,China;College of Hydraulic Science and Engineering,Yangzhou University,Yangzhou 225009,China)
出处
《南水北调与水利科技（中英文）》
CAS
北大核心
2022年第4期765-772,共8页
South-to-North Water Transfers and Water Science & Technology
基金
国家自然科学基金项目(51779214)
江苏省南水北调科技研发项目(SSY-JS-2020-F-43、SSY-JS-2020-F-45)
江苏省水利科技项目(2020030)。
关键词
贯流泵
单向流固耦合
数值模拟
应力应变
模态分析
tubular pump
one-way fluid-solid coupling
numerical simulation
stress-strain
modal analysis
