液力透平蜗壳内非定常压力脉动的研究  

RESEARCH ON UNSTEADY PRESSURE FIELD WITHIN A HYDRAULIC TURBINE VOLUTE

作　　者：杨孙圣[1] 孔繁余[1] 成军[1] 黄志攀[1] 张新鹏[1] 

机构地区：[1]江苏大学流体机械及工程技术中心,江苏镇江212013

出　　处：《工程力学》2013年第2期388-393,共6页Engineering Mechanics

基　　金：国家科技人员服务企业行动项目(2009GJC10007);江苏大学博士创新基金项目(CX10B_012X)

摘　　要：液力透平内部流场的非定常压力脉动是影响机组运行稳定性的关键因素之一,为了研究液力透平蜗壳内部的压力脉动,采用流场分析软件对一单级液力透平内部流场进行了三维定常和非定常数值模拟,对蜗壳流道内不同周向位置、径向位置和不同流量时的压力脉动进行了时域和频域分析。结果表明:在一个叶轮旋转周期内蜗壳内压力的脉动数量等于叶片数;蜗壳入口位置和割舍位置处压力脉动较小,蜗壳环形部分中部和割舍前端位置处压力脉动较大;蜗壳内压力脉动的主频和次主频分别为叶频和2倍叶频;液力透平蜗壳内部的压力脉动程度在小流量下较小,随着流量的增加,压力脉动程度逐渐增加,大流量时最为剧烈。为了验证数值计算的准确性,建设了开式液力透平试验台,制造了模型样机对液力透平进行了外特性试验和非定常压力脉动测量,验证了数值计算的准确性。The unsteady pressure pulsation of an internal flow field within a hydraulic turbine is one of the major factors affecting the stability of a turbine unit. Computational Fluid Dynamics software was adopted in the steady and unsteady flow filed analyses. Time and frequency domain analyses were performed on the data acquired at different circumferential positions, radial positions and flow rates. Results show the number of pressure pulsation within one impeller rotational cycle equals a blade number. The amplitude of pressure pulsation at the volute inlet pipe and cut water is minor, however it is intensive at the middle of a volute spiral part and before the cut water. The main frequency and secondary main frequency of pressure pulsation within a volute are blade frequency and two times of blade frequency. Investigation into pressure pulsation at different flow rates shows that the amplitude of pressure pulsations increases with flow rates. To verify the numerical result, the investigated hydraulic turbine was manufactured and an open hydraulic turbine test ring was built. The performance and unsteady pressure pulsations of the hydraulic turbine were acquired through experimental research. The validity of numerical simulation is confirmed through the comparison between experimental and numerical results.

关 键 词：液力透平 压力脉动 非定常流场数值模拟 蜗壳 实验研究 

分 类 号：TH322[机械工程—机械制造及自动化]