摘要
为了研究离心泵不同工况下的流动分离现象,本文以低比转速离心泵为研究对象,基于LES数值计算探索了泵内不同工况下的流动结构,利用在闭式试验台的性能试验来验证数值计算的准确性,发现泵最高效率点在1.1Q_(d)左右,在设计流量下,LES计算误差小于1.5%。通过叶轮出口流场结构分布特点,对不同工况下的流动分离现象进行对比分析,获得叶轮扫掠隔舌过程中出口流动分离现象的变化特性,及其对叶轮内流场结构的影响。结果表明:流动分离现象表现为分离泡会在叶片表面形成回流,使叶轮出口流动呈现不均匀分布特性,加强射流-尾迹结构。特别在小流量工况下,流动分离为出口旋涡的旋转提供能量,造成出口流道大面积堵塞,堵塞面积可达55%左右,诱发小流量的驼峰现象。
In order to study the flow separation phenomenon of centrifugal pump under different working conditions,the low specific speed centrifugal pump was used as the research object to explore the flow structure in the pump under different working conditions based on LES numerical calculation,and verify the accuracy of numerical calculation by using the performance test on the closed test bench.It was found that the highest efficiency point of the pump is at the location of about 1.1Q_(d),and under the designed flow rate,the LES calculation error is less than 1.5%.Based on the distribution characteristics of flow field structure at the outlet of the impeller,the flow separation phenomenon under different working conditions was compared and analyzed,and the changing characteristics of flow separation phenomenon at the outlet in the process of the impeller sweeping the tongue and its influence on the flow field structure in the impeller were obtained.The results show that the flow separation phenomenon appears as reflux formation of the separation bubbles on the blade surface,which makes the flow at the outlet of the impeller present uneven distribution characteristics and strengthens the jet-wake structure.Especially under the condition of low flow,flow separation provides energy for the rotation of outlet vortex,resulting in large area blockage of outlet flow passage,with the blocked area up to about 55%,inducing the hump phenomenon of small flow.
作者
张宁
郑凡坤
刘晓凯
蒋俊贤
ZHANG Ning;ZHENG Fankun;LIU Xiaokai;JIANG Junxian(School of Energy and Power Engineering,Jiangsu University,Zhenjiang 212013,China;Harbin Electric Machinery Factory,Harbin 150036,China)
出处
《流体机械》
CSCD
北大核心
2023年第8期27-32,共6页
Fluid Machinery
基金
国家自然科学基金项目(517006086)。
关键词
离心泵
大涡模拟
回流
旋涡
centrifugal pump
large eddy simulation
backflow
vortex
作者简介
张宁(1987),男,硕士研究生导师,副教授,主要从事流体机械内部复杂流动及流激特性研究,E-mail:nzhang@ujs.edu.cn;通信作者:郑凡坤(1997),男,硕士研究生,主要从事流体机械内部复杂多相流动及流激振动研究,通信地址:212013江苏省镇江市江苏大学能源与动力工程学院,E-mail:616978099@qq.com。
