Liquid viscosity measurement method in the pressure range of 0.1~0.5 MPa based on Couette rheometer

WANG Kun, JIA Zheng, FAN Yurun
(State Key Lab of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027, China)

Abstract: In order to research the method of liquid viscosity measurement in the pressure range of 0.1 MPa~0.5 MPa using the Couette rheometer, strength check of the rheometer was done firstly. The result shows that the rheometer can work safely in the pressure less than 4.2 MPa. Secondly, the problem of how to get the torque of the working section from the output torque of the motor was solved. Finally, according to the proportional relationship between the viscosity of liquid and the output torque of the working section, the way of computing the liquid viscosity through the torque of working section indirectly was summarized. The error analysis results show that, the relative error of viscosity measurement is about 7%. The work makes a good foundation for the research of the influence of the amount of air absorbed in the liquid to the viscosity of it and the mechanism of cavitation.
Key words: Couette rheometer; strenghth check; viscosity measurement; torque calibration; error analysis