Problem 91P

A fireboat is to fight fires at coastal areas by drawing seawater with a density of 1030 kg/m3 through a 20-cm-diameter pipe at a rate of 0.1 m3/s and discharging it through a hose nozzle with an exit diameter of 5 cm. The total irreversible head loss of the system is 3 m, and the position of the nozzle is 3 m above sea level. For a pump efficiency of 70 percent, determine the required shaft power input to the pump and the water discharge velocity.

Solution

Introduction

The water is discharged through the nozzle exit having diameter 5 cm and the total irreversible head loss of the system is 3 m and the nozzle is 3 m above the sea level .

Step 1

The water discharge through the nozzle end the velocity is given by

The area