Abstract: By utilizing the newly developed visual Couette rheometer with its outer cylinder rotating and pressure adjustable, cavitation experiments of strong shear flow are carried out. It is found that the influence of transient temperature and shearing torque on shearing cavitation is very obvious. By experimental data of temperature step response of sensor, the convection heat transfer coefficient when the thermocouple is rooted in resting hot liquid and subjected to the step temperature change is obtained. In a cylindrical coordinate system, with the pure shearing torque and transient heat transfer differential equation obtained from the experiment, the transient temperatures of strong shearing Couette flow at different time are calculated by using numerical method. The theoretical value is consistent with the experimental result, thus showing the correctness of pure shearing torque and transient temperature and the uniformity of gap obtained from the said Couette rheometer by using the preliminary estimation method, the temperature change value of strong shearing Couette flow is obtained. The comparison and analysis results show that the proposed method is highly accurate and widely applicable.

Key words: Couette rheometer, Shearing cavitation, Transient heat transfer