毛细管狭缝流变仪的测量原理和应用

PRINCIPLE OF MEASUREMENT IN A CAPILLARY NARROW RHEOMETER AND ITS APPLICATION

介绍一种能自动连续测量的毛细管狭缝流变仪的原理和结构，该流变仪具有微机自控和数据采集处理系统，适用于牛顿液体和石油钻井泥浆等非牛顿流体流变性能的在线和离线测量。文中推导出毛细管狭缝流变仪测量适用于罗伯逊一斯蒂夫模式、幂律模式、宾汉模式的流变参数、剪切应力、剪切速率和雷诺数的有关计算公式。通过实测资料证明，该流变仪测量精度较高，自动测量相对误差≤３％，手动测量相对误差≤１％，具有广泛的实用性。

This paper presents the principle and structure of a capillary narrow rheometer whichcan measure the rheology of any fluid automaticlly and continuously. The rheometer is con-trolled automatically by a microcomputer which can acquisite and process data obtained.Itwill be applied to on-line and off-line measurements for Newtonian fluid and non-Newtonianfluid such as rheological properties of drilling fluids mud etc. This paper deduces rheologicalparameters, shear stress, shear rate and Reynolds′number used in the formula of capillarynarrow rheometer measurements for Robertson & Stiff,Index and Bingham model. The mea-sured data proves that the rheometer′s measurements are precise,with a relative error of lessthan 3% by automatic measurements,and a relative error of less than 1% by manual opera-tion.