The viscosity of liquids can be measured through the use of two concentric cylinders. In this device, the fluid is filled in between the cylinders. During the measurement, the outer cylinder is fixed and the inner cylinder is rotated with an angular velocity. The torque required to develop is measured, and the viscosity is calculated from these two measurements.
Develop an equation relating µ (viscosity), τ (Torque), n (inner cylinder rotation speed), ι (gap between the cylinders), and Ri (inner cylinder radius) to determine the viscosity of fluids. Neglect end effects and assume the velocity distribution in the gap is linear.
For this viscometer, if L = 50 cm, Ri = 130 mm, ι = 2 mm, n = 300 rpm, τ = 4 Nm, then determine the viscosity of the fluid to be tested.
