Chapter 2, Problem 86P

A rotating viscometer consists of two concentric cylinders-a stationary inner cylinder of radius $R_i$ and an outer cylinder of inside radius $R_0$ rotating at angular velocity (rotating rate) ${\omega }_0$ . In the tiny gap between the two cylinders is the fluid whose viscosity( $\mu$ )is to be measured. The length of the cylinders (into the page in Fig. P2-86) is L. L is large such that end effects are negligible (we can treat this as a two-dimensional problem). Torque (T) is required to rotate the inner cylinder at constant speed. Showing all your work and algebra, generate an approximate expression of T as a function of the other variables.