摘要
为了揭示不同进口流速情况下90°方形弯管内部流动特征,在构建90°方形弯管专用PIV试验台的基础之上,对弯管内不同断面以及不同半径上的流速分布情况进行了PIV测试试验。试验结果表明:采用PIV技术能较好地获得弯管内部流动情况;流体未进入弯曲段时,各断面流速分布变化不大;而进入弯曲段后,由于受到弯管壁的约束形成旋转流动,弯管内侧流速增大,外侧流速降低;当转过60°位置后,弯管内侧流速降低,外侧流速增加;到达90°位置后,各断面的流速基本趋于一致。不同半径处的流速分布不相同,弯管内侧流速较大,外侧较小,在50°、60°处流速达到最大值;弯管不同的进口流速对于速度峰值的位置有一定的影响,而对于弯管内其他的流动情况影响较小。
In order to reveal the internal flow characteristics of a 90° bending duct with square section at different inlet velocities,PIV measurements of velocity distribution were carried out for bending ducts at different sections and radii.The experimental results suggest that the flow behavior within a bending duct can be measured by PIV.Velocity profiles vary little before the fluid entering the bending section.Rotating flow forms due to the restraint of the bending wall when the fluid enters the bending section,resulting in a velocity increase at the inner wall of the bending duct and a velocity decrease at the outer wall of the bending duct.On the contrary,the velocity decreases at the inner wall of the bending duct and increases at the outer wall of the bending duct when the fluid passes through 60°.Flow velocity tends to be uniform when the fluid passes through 90°.Velocity profile was different with different radius and the velocity near the inner wall is higher than that near the outer wall.Maximum velocity occurs at 50° and 60°,and its location is found to be dependent on the inlet velocities and independent on other flow characteristics in the bending duct.
出处
《水利水电科技进展》
CSCD
北大核心
2013年第5期31-34,56,共5页
Advances in Science and Technology of Water Resources
基金
国家自然科学基金(51179075)
江苏省工业科技支撑计划(BE2012131)
江苏省研究生创新计划(CXZZ12_0680)
江苏大学高级人才启动基金(12JDG082)
关键词
90°方形弯管
粒子图像测试
流场分析
双叶片泵
90° bending duct with square section
particle image velocimetry
flow analysis
double-blade centrifugal pump
