A centrifugal pump impeller is rotating at (1200 mathrm{rpm}) in the direction shown in Fig. P12.9. The

Question:

A centrifugal pump impeller is rotating at $1200 \mathrm{rpm}$ in the direction shown in Fig. P12.9. The flow enters parallel to the axis of rotation and leaves at an angle of $30^{\circ}$ to the radial direction. The absolute exit velocity, $V_{2}$, is $90 \mathrm{ft} / \mathrm{s}$.

(a) Draw the velocity triangle for the impeller exit flow.

(b) Estimate the torque necessary to turn the impeller if the fluid is water. What will the impeller rotation speed become if the shaft breaks?

Figure P12.9