EXPERIMENTAL INVESTIGATION OF GEOMETRY ON TORQUE HYSTERESIS BEHAVIOUR OF TAYLOR-COUETTE FLOW

etc15 Tracking Number 317

This study investigates the effect of the Taylor-Couette geometry, namely the aspect ratio, Γ, and the gap width ratio, ƞ, on the torque hysteresis reported by [1]. Measurements were taken at two shear Reynolds numbers, Res, of 5.5x104 and 9x104.The torque was recorded while decreasing or increasing the rotation frequency ratio a=-fo/fi, keeping the rotation frequency difference fi-fo constant, where fo and fi are the outer and inner cylinder rotation frequencies, respectively. Results obtained for Γ=22 and ƞ=0.917 at Res of 5.5x104 and 9x104 show hysteresis occurring in the torque data. Interestingly the hysteresis behaviour is opposite to what was reported before [1], ie. torque is highest for decreasing a. Further studies will be performed to understand whether this hysteresis is due to the geometry itself and whether there is a relation between the this phenomenon and the flow structures of the Taylor-Couette flow.