摘要
传统认为,旋转粘度计的剪切速率与外筒转速的比值为1.703,实际上这一关系只适用于牛顿流体。使用旋转粘度计进行非牛顿流体测量时,二者关系将发生变化。本文从流体的动量平衡微分方程出发,对旋转粘度计的工作原理进行了阐述。同时推导出了宾汉流体、幂律流体和卡森流体,三种流体测量时剪切速率与外筒转速的关系式。并以此计算出了各流变模式下流变参数的修正公式。结果表明,具有屈服值的流体,其屈服值测量误差在6%以上。
In traditional opinion,the ratio of shear rate to rotational speed of in rotational viseometer is 1.703. Actually, this correlation is only suit for Newton fluid. When non-Newton fluids are tested by rotational viscometer, the correlation will change. Momentum balance equation was used to dsrivate the working principle of rotational viseometer in this paper. Then correlation between shear rate and rotational speed of outer cylinder is computed when Bingham fluid, power law fluid and Casson fluid were tested by rotational viscometer. Equations of rheologieal parameter deviation for each fluid were listed, too. Results show that the deviations of yield values are above 6% when yield-fluids are tested.
出处
《科技视界》
2013年第30期297-298,共2页
Science & Technology Vision
关键词
旋转粘度计
动量平衡微分方程
非牛顿流体
流变参数
误差
Rotational viseometer
Momentum balance equation
Non-Newtonian fluid
Rheological parameter
Deviation
