Question

What is the fan power required to increase the pressure of air flowing in a duct from 105 kPa to 106 kPa when the duct size reduces from its starting area of 0.45 m2 to its final area of 0.25 m2 ? The volumetric flow rate is 1.5 m3 /s. Assume no friction. Provide your answer in kW. [Ws = 1.52 kW]

Answer 1

1.52 kw

Step-by-step explanation:

A1 = 0.45

A1 = 0.25

Flow rate = 1.5m³/sec

P1 = 105

P2 = 106

P-air = 1.225kg/m³

I applied bernoulli's equation as I continued (check the attachment)

hp = 83.21371+1.3686 = 84.4823

Pf = p-air x g x Q x hp

Pf = 1.225x9.81x1.5x84.4823

Pf = 1522.868W

When converted to KW we get

Pf = 1.52 KW

Thank you!