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依据流体剪切形变的原理,导出了圆管中流体的剪切速率分布函数和当量剪切速率计算公式,提出了管道湍流的脉动剪切速率概念及其计算方法。按照当量剪切强度相等的原则,给出了管道层流与湍流及粘度计之间的等效剪切模拟基础,并指出通常把工业管道的管壁剪速怍为当量剪切速率来模拟管道湍流剪切是不准确的,特别是高雷诺数时,把管壁剪速看作当量剪切速率的模拟试验会严重扩大工业管道中管流剪切的影响。文中给出的计算方法和模拟方法,可为管道设计、运行和管理提供较准确的科学依据。
According to the principle of fluid shear deformation, the formulas of shear rate distribution and equivalent shear rate of the fluid in a circular tube are deduced. The concept of the pulsation shear rate of pipeline turbulence and its calculation method are proposed. According to the principle of equivalent shear strength equal, the equivalent shear simulation between pipeline laminar flow and turbulent flow and viscometer is given. It is pointed out that the pipe wall shear rate of industrial pipe is usually used as the equivalent shear rate to simulate the pipe Turbulent shear is inaccurate. Especially at high Reynolds numbers, the simulation of tube wall shear rate as the equivalent shear rate severely expands the effects of shear in industrial pipes. The calculation methods and simulation methods given in this paper can provide more accurate scientific basis for pipeline design, operation and management.