湍流发生器径比对剪切室内流体黏度的影响  

Effect of turbulence generator diameter ratio on fluid viscosity in shear chamber

作　　者：刘在伦[1,2] 王虎 芦维强 苏丹枫 LIU Zailun;WANG Hu;LU Weiqiang;SU Danfeng(College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou,Gansu 730050,China;Engineering Institute of Wenzhou Pump&Value,Lanzhou University of Technology,Wenzhou,Zhejiang 325105,China;College of Environmental and Chemical Engineering,Chongqing Three Gorges University,Chongqing 404000,China)

机构地区：[1]兰州理工大学能源与动力工程学院,甘肃兰州730050 [2]兰州理工大学温州泵阀工程研究院,浙江温州325105 [3]重庆三峡学院环境与化学工程学院,重庆404000

出　　处：《排灌机械工程学报》2020年第11期1145-1151,共7页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(51269010);浙江省自然科学基金资助项目(LY12E09002)。

摘　　要：为了了解湍流发生器径比对剪切室内流体黏度的影响,提出了一种新的湍流发生器设计方法,设计出5种不同径比的湍流发生器方案.在径比为0.5,0.6,0.7,0.8,0.9时,以浓度为12.5%的卫生纸浆作为介质进行数值模拟,引入黏度均值和黏度标准差的概念,对剪切室内黏度分布情况进行了分析.结果表明:在径比由0.5增加至0.9的过程中,剪切室内流体黏度的整体值逐渐降低,且径比为0.7时,剪切室内质点黏度分布最均匀.在剪切室内取不同轴向截面后发现,随着径比系数增大,剪切室进口出现明显的高低黏度流体分离现象,出口处流体黏度逐渐减小.同一截面内流体黏度在半径方向呈规律性变化,且在湍流发生器叶顶部位存在黏度极小值,径比增大过程中,其值逐渐减小,并沿半径增大方向移动.To find out influences of turbulence generator diameter ratio on pulp viscosity in a shear chamber,a new design method was proposed for the turbulence generator.Five turbulence generators with different diameter ratios,namely 0.5,0.6,0.7,0.8 and 0.9 were designed.Then the viscosity distribution in the shear chamber with these generators was analyzed in terms of the mean and standard deviation of the viscosity based on CFD numerical simulations when the sanitary pulp with 12.5%consistency was used as pumped medium.It turned out that the whole value of fluid viscosity in the shear chamber decreased gradually as the diameter ratio raised from 0.5 to 0.9,and the viscosity distribution in the chamber was the most uniform when the diameter ratio was 0.7.In different axial cross-sections in the chamber,it was found that with increasing diameter ratio a phenomenon where the fluid with high viscosity was separated from the fluid with low viscosity that occurred at the inlet to the chamber,and the fluid viscosity at the outlet to the chamber decreased gradually.In the same section,the fluid viscosity varied regularly in the radius direction,and there was a minimum viscosity at the tip of the turbulence generator.As the diameter ratio was increased,the minimum viscosity was lower gradually,and its position moved along the increasing radius direction.

关 键 词：湍流发生器 中浓纸浆 径比 Heschel-Bulkley流体模型 黏度 

分 类 号：S277.9[农业科学—农业水土工程]