# Question: a saturated steam flow of 08 kgs enters a vertical...

###### Question details

A saturated steam flow of 0.8 kg/s enters a vertical pipe, internal diameter 15 mm, at a pressure of 100 bar, and a vapour mass fraction of 0.3, as shown in the diagram.

After 4 m the internal diameter increases to 30 mm and remains uniform for 20 m.

( i) Determine the flow regimes in the two pipe sections

(ii) Determine the pressure drop due to gravity and friction.

Use Thom’s correlations (homogeneous model) for the two phase
multiplier and void fraction and note that the frictional pressure
drop will be due to the wall friction for the 4 and 20 m pipes and
a pressure drop due to the sudden expansion. For the single-phase
friction factor use the following equation for the Darcy friction
factor.

f = 0.184Re ^-0.2

(iii) Investigate the effect of pressure on the above solutions by
calculating for saturated conditions at 150 bar and 180 bar.