Compressible Flow, Design of Pumps and Compressors

Worked Example 1.

(i) A horizontal pipeline 900m long and 75mm diameter, conveys compressed air

isothermally at a temperature of 18C. If the gauge pressure at the inlet is

1240 kN m-2

, at the outlet is 380 kN m-2

and the friction factor is f = 0.0045,

determine the mass flow rate in the pipe.

R = 287 j kg-1

K-1

Patm = 101 kN m-2

(ii) Determine the critical pressure and the maximum flow rate for the conditions

outlined above. Was it valid to use equation (19) to solve part (i)?

Worked Example 2.

An ideal gas in steady state flows adiabatically along a horizontal pipe of 0.02m

diameter. The pressure and density at a point are P = 20,000 Nm-2

, = 200 kg m-3

The density drops to 100 kg m-3

over a 5m length of pipe. Calculate the mass flow

rate per unit area.

f = 0.009

= 1.40