石油学报 ›› 2002, Vol. 23 ›› Issue (5): 88-90.DOI: 10.7623/syxb200205018

• 石油工程 • 上一篇    下一篇

利用能量耗散率计算管流的平均剪切率

张劲军, 严大凡   

  1. 石油大学油气储运工程系, 北京昌平, 102200
  • 收稿日期:2001-09-11 修回日期:2002-01-04 出版日期:2002-09-25 发布日期:2010-05-21
  • 作者简介:张劲军,男,1962年3月生,1998年毕业于石油大学(北京)油气储运工程专业,获博士学位,现为石油大学(北京)油气储运工程系主任、教授、博士生导师.
  • 基金资助:
    中国石油天然气集团公司"九五"科技攻关项目,教育部博士学科点专项科研基金资助项目(1998042517).

Calculation of average shear rate in pipe flow based on energy dissipation rate

ZHANG Jin-jun, YAN Da-fan   

  1. University of Petroleum, Beijing 102249, China
  • Received:2001-09-11 Revised:2002-01-04 Online:2002-09-25 Published:2010-05-21

摘要: 含蜡原油的流变性与其所经历的剪切历史有关.以往用截面平均剪切率或湍流时的管壁剪切率衡量流体管流的剪切历史,有不当之处.根据能量耗散率与剪切率的关系,提出了按流体的体积平均能量耗散率计算流体平均剪切率的方法,即可根据流体的密度、平均流速、管道直径、流动的摩擦因子或摩阻压降以及流变参数计算牛顿流体和幂律流体管流的平均剪切率.对于湍流,按本方法计算的平均剪切率能合理地度量流体的平均剪切历史.在原油管道正常运行的雷诺数范围内,按截面平均方法计算的湍流剪切率比按体积平均能量耗散率计算的结果约偏低20%~40%.

关键词: 管道, 流体流动, 石蜡基原油, 平均剪切率, 剪切历史, 湍流, 能量耗散率, 计算方法

Abstract: Flow properties of a waxy crude are influenced by shear history.The cross-sectional average shear rate or the shear rate at the pipe wall in turbulent flow was unreasonably used to evaluate shear history in pipe flow.According to the relationship between the shear rate and the energy dissipation rate,a method for calculating the average shear rate based on the volumetrically average energy dissipation rate is presented.This method may be easily used to calculate the average shear rate in pipe flow of the Newtonian and the power law fluids according to the fluid density,average velocity,pipe diameter,the frictional factor or frictional pressure drop,and the rheological parameters.The average shear rate obtained with this method is a more reasonable measurement of the average shear history of fluid in turbulent pipe flow.Within the range of the Reynolds number commonly encountered in crude oil pipelines,the cross-sectional average shear rate of pipeflow is less by 20%~40% than that calculated by using the presented method.

Key words: pipeline, fluid flow, paraffin-base crude, average shear rate, shear history, turbulent flow, energy dissipation rate, calculation

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