[Emaddaneshyar]

I'm trying to model the draining of pressurized hot water (in saturated state) from a tank to the atmosphere through a pipe.

You know because of decrease in pressure some of water changes to vapor (consequently decrease in temperature happens). In other words we have flashing flow here.

I've used mixture and evap/cond model. Furthermore, I'm giving to the density of vapor the temperature-dependent values (piecewise linear).

The simulation is running (evaporation occurs and pressure and temperature decreases) but I don’t see any change in density of vapor(phase2 density).
I don’t understand what does it mean? Please help me. Thank you!