同轴圆筒旋转粘度计测量误差的分析与修正

Analysis and Correction for Measurement Errors of Coaxial Cylinder Viscometers

在使用同轴圆筒旋转粘度计进行实际测量时,由于实验条件与假定理想条件不符会产生测量误差。本文重点分析了Physica MCR301同轴圆筒旋转粘度计中牛顿流体、幂律流体、屈服假塑性流体及递减硬化固体材料的剪切速率、剪切应变和剪切应力的分布规律,以及由流体本构方程导致的稳态测量误差和由仪器测量系统本身惯性引入的瞬态测量误差。结合实验对稳态测量误差进行迭代逼近法修正,对瞬态测量误差由实测剪应力减去系统惯性力进行修正,这对测量非牛顿流体的流变性有重要意义。

When using coaxial cylinder viscometer,measure error was caused by the inconsistency between experiment condition and ideal condition.This paper analyzes the shear rate,shear strain,shear stress distribution law of Newtonian liquid,Power-law fluid,Yield pseudoplastic fluid and reduced hardening solid materials in Physica MCR301 coaxial cylinder viscometer.It also analyzes steady-state measure error caused by constitutive equation of fluid and simultaneous measure error introduced by the inertia of instrument measuring system.The former can be modified by iteration and approximation,the latter is modified by subtracting inertial force from shear stress.It is important for measuring the rheology of Non-Newtonian liquid.