Match the following pairs that represent power in watts and

Match the following pairs that represent power, in watts, and place them in order from smallest to largest. A water pump has a flow rate of 0.05m^2/s at a head of 16.327m. The motor driving the pumps Provides 53.05 N-m of torque at a speed of 188.5 rad/s (1800 rpm) What is the water horsepower? What is the brake horsepower? What is the efficiency of the pump? A water pump has an impeller diameter of 1.0375 m, and when it runs at 75 rad/s, it output 1.325 m^2/s at head of 82 m. Suppose a second pump is considered with a 0.95 m impeller to be run at 85rad/s what would be the flow rate of the second pump, in m^2/s? What would the second pump\'s head, in meter? What would be the ratio of the second pump;s power requirement to the first one\'s?

Solution

1. )

C. 440 volts * 67 Amps = 3080 W

A. 900 Newtons * 30 meters/ s = 27,000 W

D. 500,000 Pa *0.064 m^3/ s = 32,000 W

E. 90 N-m * 360 rad/ s= 32,400 W

B. 100,000 Jouls divided by 3 seconds= 33,333 W

2.

A) the preassure is P=density*gravity*higth= 1000*9.81*16.327 = 160168 Pa

The power is 160168*0.05 m^3/s = 8008.39 W= 10.88 Hp

B)53.05*188.5=9999.93 W = 13.5912

C. efficiency= 10.88/13.5912 = 0.8

3.)

A- Q1/Q2= D1^3 / D2^3

Q2= (0.93^3 / 1.0375^3 )*1.325 = 0.954334 m^3/s

B) H2/H1= D2^2/D1^2

H2=(0.93^2 / 1.0375^2 )*82 = 65.8876 m

C) Power 2 / power 1 = H2*Q2/ H1*Q1= 65.8876*0.954334 / 82*1.325 = 0.578428