摘要
为了研究添加表面活性剂在供热管道局部构件处的减阻效果,选取三通构件模型,利用计算流体力学软件模拟管内不同雷诺数下纯水和CTAC/NaSal溶液的流动。通过网格无关性、对比减阻规律验证了Carreau-Bird模型的可靠性,着重分析了减阻率、流速分布和湍动能的变化,并采用Ω准则和Q准则分析三通涡结构变化。结果表明:三通中添加CTAC溶液,减阻效果小于直管,但在较小雷诺数下就达到减阻率最大值;添加CTAC溶液改变了三通内流速分布,会使管内低速流动区域减小,而高速流动区域增大,出口段湍流流动层流化;降低了壁面附近的涡量,但增加了涡旋中心区的涡量。
In order to study the drag reduction effect of adding surfactants on local components of heating pipelines,a three-way component model is selected,and CFD software is used to simulate the flow of pure water and CTAC/NaSal solution in the pipe under varying Reynolds numbers.The reliability of the Carreau-Bird model is verified by grid independence and comparison of drag reduction laws.The laws of drag reduction rate,flow velocity distribution,and changes in turbulent kinetic energy are emphatically analyzed,and theΩcriterion and Q criterion are used to further analyze the changes in the three-way vortex structure.The results demonstrate that,in comparison with a straight pipe,adding a CTAC solution in the tee results in a smaller drag reduction effect.Still,the maximum drag reduction rate is reached at a small Reynolds number.The addition of CTAC solution increases the flow velocity in the main pipe and alters the flow velocity distribution with the tee,leading to a reduction in the low-speed flow area and an increase in the high-speed flow area.This promotes laminar fluidization of the turbulent flow at the outlet.Simultaneously,it diminishes vorticity near the wall while augmenting vorticity in the central region of the vortex.
作者
张志
张浩
李茂林
石若冉
ZHANG Zhi;ZHANG Hao;LI Maolin;SHI Ruoran(School of Thermal Engineering,Shandong Jianzhu University,Jinan 250101,China;Shandong Collaborative Innovation Center of Green Building,Jinan 250101,China)
出处
《山东建筑大学学报》
2024年第1期48-56,共9页
Journal of Shandong Jianzhu University
基金
山东省专业学位研究生教学案例库项目(SDYAL20162)
山东省研究生优质课程建设项目(SDYKC19117)。
关键词
表面活性剂减阻
三通
涡分析
数值模拟
surfactant drag reduction
three-way
vortex analysis
numerical simulation
