Question

A pump draws water from a reservoir through a 150 mm diameter suction pipe and delivers it to a 75 mm diameter discharge pipe.

Answer 1

Answer:

3.42 kW

Explanation:

calculate the mass flow rate of the water = density * velocity * area

= 13.3 kg/s

where Area of pipe  =  π/4 * d^2 =  π/4 * 0.075^2 m  =  0.0044 m^2

given that : 1 Kg = 1 N s^2 / m,      1 Watt = 1 N m /s

calculate : power produced by discharge pipe

Discharge Pressure x Volume flow =

Pressure  * Area * velocity

P  * 0.0044 * 3  = 2253 N m /s

calculate: power due the mass of water  

mass of water * 2  = 258 N m/s

where:  mass of water = density * volume

Calculate power produced due the velocity of exiting water

= m * V2/2 = 59.4 N m/s

hence The  power added to fluid = 2253 watts

power added to the fluid by pump = 2253 / 0.75 = 3.42 kW