Hello, I am trying to run a combustion model inside a tube with two small inlets (air\fuel) and and outlet. When i was using a standard outlet boundary the code stopped due to negative velocities. Then I changed to pressure boundary. Initialy i had the pressure reference cell at the inlet, because there I know the temperature. I specified atmospheric pressure. Since I do not know the pressure drop, i changed the reference cell to one in the pressure boundary. However there I don't now the temperature.

Has anybody got any ideas?

thanks,

thomas

For models with pressure boundary, do you really need to know the pressure at the pressure reference cell?

I'm not sure, but i think you can set your pressure reference cell at the pressure boundary and run your calculation.

For models with pressure boundary it doesn't matter where you set your pressure reference cell. Reference temperature is not associated with pressure reference cell. However to set up pressure boundary you do need to know pressure on it! So may be in your case it's better to stay with outlet boundary but extend the domain.