摘要
利用三维湍流数值模拟对某30°斜轴进水流道水力特性进行了分析,研究了设计流量工况下流道的内部流场、不同横断面和纵剖面速度等值线、出口断面速度均匀度和速度加权平均角以及流道水力损失。研究结果表明,斜式进水流道水流处于均匀渐缩,内部流态良好,无漩涡或脱流,出口断面流速分布均匀度Vu=98.2%,速度加权平均角度θ=88.42°,流道水力损失Δh=5.9cm,流道型线合理。试验研究了30°斜轴模型泵装置能量特性、空化特性和飞逸特性,得到5个叶片角度下模型和原型泵装置能量特性曲线、3个不同叶片角度下空化特性及叶片角-2°下的单位飞逸转速和单位飞逸流量。试验结果表明,模型泵装置最高效率随叶片角度减小而增大,叶片角-4°时的最高效率可达83%,较大范围运行工况下的空化性能优良,飞逸转速安全。研究结果对低扬程泵站水力优化设计具有重要的参考价值。
Turbulent flows in a 30° slanting inlet duct were simulated by a 3-D numerical model,and its velocity field,velocity contours on cross sections and uniformity of axial velocity and flow angle at the outlet were obtained.Hydraulic performance and head loss of the inlet duct were calculated and analyzed.This study reveals that the flow in this duct of gradual contraction takes a good pattern of no separation trend or vortices,producing a head loss of 5.9cm only,and that at the outlet,the uniformity of axial velocity reaches 98.2% and the flow angle is 88.42° on average.These results show that the duct shape is reasonable.Through scale-model test of a 30°slanting pump set,the characteristic energy curves at five blade angles,NPSHc at three blade angles and the runaway speed at blade angle of-2° were obtained for the model and prototype pumps.The experimental results indicate that peak efficiency increase as the blade angle decreases,with its maximum of 83% at the angle of-4°.In a great range of operation condition the measured NPSHc is satisfactory and the runway speed is safe.This work provides useful information for hydraulic optimization of low water-head pumping stations.
出处
《水力发电学报》
EI
CSCD
北大核心
2012年第3期204-208,216,共6页
Journal of Hydroelectric Engineering
基金
江苏省水利科技重点项目(200953)
关键词
水力机械
斜轴泵站
进水流道
数值模拟
泵装置
模型试验
hydraulic machinery
slanting axial pumping station
inlet duct
numerical simulation
pump set
model test
