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Pressure boundary condition in Inlet Mass Flow

Question asked by Joao Antonio on Oct 8, 2019


I am trying to simulate the discharge of a fire suppression agent inside a room to understand the dispersion of the agent and the pressure distribution in each equipment surface and on the room walls/door.


I have the noozle discharge profile, both mass flow and pressure. I inserted both in an Inlet Mass Flow boundary condition.

However, in the transient results I only get one result, that is a constant pressure all over the room, including the nozzle where I introduced the profile, and this constant pressure is equal to the equilibrium pressure for that time step.

Summarizing, I do not get a pressure variation anywhere, even where I tried to force it.

Here we can see a cut plot of fire suppression bottle. At this moment of the simulation (5 s), the inlet should be at 50 bar, however it is almost at atmospheric pressure. A surface plot in the inlet would show the exact same values-

All other results at first sight look okay to me.


 Is any physical concept escaping me? Is this a limitation of Flow, not being able to introduce a mass flow and a pressure profiles at the same time? 


Also, if someone knows the path to change the decimals of the legend I would kindly appreciate it.