Four strain gauges, with specification given below, are available to measure the torque on a cylindrical shaft 4 cm in diameter connecting a motor and load. (a) Draw clearly labelled….

## Calculate an accurate value for the differential pressure developed across the chosen Venturi, at maximum flow rate.

A Venturi is to be used to measure the flow rate of water in a pipe of diameter D = 0.20 m. The maximum flow rate of water is 1.5 × 10^{3} m^{3} h^{−1}, density is 10^{3} kg m^{−3}, and viscosity is 10^{−3} Pa s. Venturis with throat diameters of 0.10 m, 0.14 m and 0.18 m are available from the manufacturer.

(a) Choose the most suitable Venturi for the application, assuming a differential pressure at maximum flow of approximately 3 × 10^{5} Pa.

(b) Calculate an accurate value for the differential pressure developed across the chosen Venturi, at maximum flow rate. (Use the following formula for the coefficient of discharge:

where

d = Venturi throat diameter, and Re_{D} = Reynolds number referred to pipe diameter.)