摘要
以单级蜗壳式离心泵作为研究对象,基于RANS法对离心泵内部流场结构进行了三维非定常数值模拟,探讨其内部的非定常流动特征所诱发的压力脉动特性及水力激励力特性,并在叶轮旋转周期过程中重点针对叶轮及其单个叶片的受力情况进行相关分析.结果表明:不同工况下各监测点压力脉动幅值的变化规律具有一致性,静压沿蜗壳周向分布不均匀;在压力脉动频谱图及叶轮径向力频谱图中叶频均占主导地位,而单个叶片激励力则体现为轴频;单个叶片所受径向力大小随流量的增加而增大,小流量工况下单个叶片的受力不均匀性明显,而接近额定工况时各叶片受力较均匀,且相差不大;通过对单个叶片非定常激励力特性的分析可知,小流量工况下由于隔舌附近叶片出口流动分离使得叶片受力变化明显,受射流尾迹影响更为突出.
The structural mesh and k -w turbulence model were used to study the unsteady flow cha- racteristic of whole flow field in a centrifugal pump and to analyze the unsteady excitation characteristic under different working conditions. This study focused on the analysis of pressure pulsation at different locations under different working conditions and a hydrodynamic forces on the single blade, discussed the influence factor that induced the radial loading of the single blade under each revolution. It shows that, the blade passing frequency is the dominant frequency both in the pressure pulsation frequency spectrum and the impeller radial force spectrum, while the shaft frequency is the main excited frequen- cy in the radial hydrodynamic force on a single blade. The radial force on the single blade increased with the flow, the force on single blade under low flow rate conditions is nonuniform obviously while it＇s uniform close to the rated conditions or BEP. By analyzing the unsteady excitation characteristic of the single blade, the phenomenon of jet- wake at the trailing edge close to the tongue can change the blade loading significantly, the radial hydrodynamic forces is sensitive and directly related to the change of the flow structure near the volute tongue.
出处
《排灌机械工程学报》
EI
北大核心
2014年第12期1023-1028,共6页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金资助项目(51106066)
关键词
离心泵
非定常流动
压力脉动
水力激励力
centrifugal pump
unsteady flow
pressure pulsation
hydrodynamic forces
