[cramr5]

Hello,

I am trying to model the impact of the pressure increase in a "box" when a sudden burst of gas is released into it. The thing is that for outlet we will have a "valve" that will only allow flow out when internal pressure is above 100mbar.

The thing is I don't know how to model that, If I use Pressure Outlet with a pressure of 100mbar the simulation goes crazy and diverges... Any idea how? shoud I use a porous media effect?

Thanks

[Maddin]

It's a unsteady case for sure. Would start with some simple 2D case and work on that.
Wave generation via field function and go for it.
Some sinus stuff or with some excel table

[cwl]

If I use Pressure Outlet with a pressure of 100mbar the simulation goes crazy and diverges...

I guess that happens because initial pressure inside the box is much lower than the boundary pressure.

Any idea how? shoud I use a porous media effect?

Yep, it should depend on the pressure on the "valve" surface (simple circle on the wall for example). The thing is - it looks like you'll need to consider the properties of the valve like flow rate characteristic curve.

[cramr5]

Originally Posted by cwl

Yep, it should depend on the pressure on the "valve" surface (simple circle on the wall for example). The thing is - it looks like you'll need to consider the properties of the valve like flow rate characteristic curve.

That what I had in mind... create a field function with 0 flow rate until 100mbar are achieved and then increase Mass flow out following the curve of the valve. The thing is that we don't know the curve but I'll try to find something or make something up