摘要
采用标准k-ε模型对90°弯管内部流场进行了三维数值模拟研究。模拟中弯管曲率半径与管径之比β=R/d分别为2.0、2.5、3.0和3.5,表观液速为0.5m/s。通过建模和数值计算,研究了弯管内流场分布、压力分布以及速度矢量和流动轨迹等规律,并重点分析了不同β情况下的弯管中流场流动特点。结果表明:流体速度在弯管内不同截面内是逐渐变化的。由于离心力的作用,在流动后段出现二次流,加强了流体的扰动。同时,流体进入弯道后管道内部不同半径处压力不同,弯管内壁面附近处压力较小,弯管外壁面处压力较大。不同曲率半径与直径之比对管内流速分布有较大影响。β由小增大时,内侧流速逐渐变小,实际的管道设计与施工中尽量使用β较大的弯头附件以降低对管道内壁的冲击。
The characteristic of fluid flow field in 90° bend pipe was numerically simulated using the standard k-εmodel.The ratio of bend radius of curvature and diameterβ=R/d were respectively 2.0,2.5,3.0 and 3.5,and superficial liquid velocity was 0.5m/s.The flow field distribution,pressure distribution and velocity vector and the flow path were investigated,and flow characteristics under different β in 90° bend pipe were intensively studied.The results showed that the flow field in the 90° bend pipe was gradually changing.The secondary flow would appear in the back,due to the effect of centrifugal force,which strengthened the disturbance of the fluid.The pressure on both sides of the inside and outside also changed because of the bend flow.The pressure was small inside the bend,and the pressure was big outside the bend.The different ratio of bend radius of curvature and diameter had a great influence on velocity distribution.The inside velocity became gradually smaller with an increase of β.The largeβof bend pipe reduced the impact on the pipe wall in the actual pipeline design and construction.
出处
《常州大学学报（自然科学版）》
CAS
2016年第3期65-69,共5页
Journal of Changzhou University：Natural Science Edition
基金
国家自然科学基金资助项目(51574045)
关键词
90°弯管
k-ε模型
流动特点
数值模拟
90° bend pipe
k-εmodel
flow characteristics
numerical simulation
