流体黏性对输流管道运动方程及临界流速的影响  

EFFECTS OF VISCOSITY ON EQUATION OF MOTION AND CRITICAL FLOW VELOCITY OF FLUID-CONVEYING PIPE

作　　者：郭长青[1,2] 张楚汉[1] 

机构地区：[1]清华大学水利水电工程系,水沙科学与水利水电工程国家重点实验室,北京100084 [2]南华大学数理学院,湖南衡阳421001

出　　处：《力学与实践》2010年第5期10-13,共4页Mechanics in Engineering

基　　金：国家自然科学基金资助项目(50375070)

摘　　要：考虑实际流体黏性引起的管内流速非均匀分布,针对层流和两种不同的湍流流态,对理想流体情况下输流管道运动方程中的离心力项进行了修正,得到的修正系数分别为1.333(圆管层流)、1.020(光滑管壁圆管湍流)和1.037～1.055(粗糙管壁圆管湍流).根据修正后的运动方程得到的上述3种情况下的发散失稳临界流速比理想流体流动情况下依次分别低13.4%,1.0%和1.8%～2.6%.流体黏性对输流管道运动方程及临界流速的影响只与流态有关,雷诺数决定流态,而黏性系数通过雷诺数间接起作用.Considering the non-uniformity of the flow velocity distribution in a fluid-conveying pipe caused by the viscosity of real fluid,the centrifugal-force term in the equation of motion of the pipe is modified in the cases of laminar flow and two modes of turbulent flow.The modification factors are found to be 1.333,1.020 and 1.037～1.055 for laminar flow in circular pipe,turbulent flow in smooth circular pipe and turbulent flow in rough circular pipe,respectively.The critical flow velocities for divergence in the above-mentioned three cases are found to be 13.4%,1.0%and 1.8%～2.6%,respectively,lower than those for ideal fluid flow.The effects of fluid viscosity on the equation of motion and the critical flow velocity of fluid-conveying pipe are explicitly related to the flow mode only.The viscosity coefficient plays an implicit role via Reynolds number,which determines the flow mode.

关 键 词：黏性 输流管道 运动方程 临界流速 

分 类 号：O317[理学—一般力学与力学基础]