基于流固耦合的离心泵蜗壳结构分析与优化  

Analysis and optimization of structure in centrifugal pump based on fluid-structure interaction

作　　者：王海宇[1] 张德胜[1] 施卫东[1] 张磊[1] 

机构地区：[1]江苏大学国家水泵及系统工程技术研究中心,江苏镇江212013

出　　处：《排灌机械工程学报》2014年第6期472-476,499,共6页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家科技支撑计划(2012BAB17B02-4;2011BAF14B01);江苏省产学研联合创新资金是瞻性联合研究项目(BY201306503);江苏省普通高校研究生科研创新计划项目(CXLX13_661)

摘　　要：为了研究蜗壳和超厚离心泵叶片匹配时的应力分布和变形,采用单向流固耦合方法对3种蜗壳结构产生的变形、等效应力和模态进行了数值分析和优化.蜗壳基圆直径与叶轮直径的比值(D_3/D_2)是蜗壳结构动力特性的主要影响因素,所以选取不同的D_3/D_2设计方案,进行数值模拟.当D_3/D_2较小时(方案A),超厚叶片出口的射流一尾迹现象导致蜗壳流道内压力分布不均匀,其诱导的蜗壳变形量较大;随着D_3/D_2逐渐增大(方案B,C),蜗壳的动力特性参数数值明显减弱,且数值趋于稳定.在设计工况下,方案A变形量最大值为544μm,等效应力最大值为15.7 MPa;方案B和方案C最大变形量分别降低为方案A的2.6%,2.8%,最大等效应力分别降为方案A的14.8%,22.9%.数值计算结果表明,3组对比方案中,方案B和方案C的结构动力特性相近,方案B的各指标最好,其运行可靠性更高.因此推荐具有超厚叶片的离心泵蜗壳D_3/D_2取1.13(方案B所取值)左右,以获得较优的结构动力特性.In order to optimize the matching of impeller with extra-thick blades and volute in a centrifugal pump,the structure displacement,equivalent stress and modes of different volutes were simulated by one-way coupling Fuild- Structure Interaction method.The ratio between basic circle diameter of volute and impeller diameter（D3/D2） is the main impact on the dynamic characteristics of volute,so it was chosen to design the simulation.When D3/D2 is small（case A）,the un-uniform velocity distribution induced by jet- wake in blade outlet leads to the strong pressure pulsation and vibration of volute.However,dynamic parameters are weakened and tend to be stable when the ratio D3/D2 gradually increases（case B,C）.Under the design conditions,the maximum displacement in case A is 544 pjn,and the maximum equivalent stress is 15.7 MPa.In case B and C,the maximum displacement is reduced to 2.6%,2.8%of case A,respectively,and the maximum equivalent stress is reduced to 14.8%,22.9%,respectively.The numerical results of the three cases show that case A and B have similar dynamic characteristics,while case B is more stable.Consequently,it is recommended that,D3/D2 should be plausible around 1.13,which is chosen in case B,in designing a volute of centrifugal pumps with extra thick blades,for a good dynamic characteristics.

关 键 词：离心泵 蜗壳 单向流固耦合 等效应力 优化设计 

分 类 号：TH312[机械工程—机械制造及自动化]