Learning Forum

[yelyaa]

Hello,

I'm trying to simulate the effects of a nitrogen spill in a room, considering it has four outlets with specific mass flow rates, a pressure inlet and a nitrogen mass flow inlet.

I cannot impose a mass flow rate at the outlets as the model does not allow it, neither use the outflow bc with massflow rate weights as I get a warning because I'm using compressible model (Reidlich Kwong) for the nitrogen.

I have tried the species model but it takes ages compared to the mixture model

Does anybody knows how if I can workaround this ?

Many thanks

[Rob]

What are you trying to model? Multiphase will need a phase interaction assuming the release is a liquid and it flashes, so will be very transient. 

[yelyaa]

Hello
I'm trying to model a transient case for a Nitrogen spill in a room with ventilations. Two phases are present it's the air and the nitrogen. Over 37 min I want to see the effect of the ventilations (4 mass flow outlets) on the accident, represented by the nitrogen mass flow inlet on the floor.

[Rob]

Does the nitrogen evaporate? Why do you need a fixed mass out? 

[yelyaa]

Yes, the nitrogen evaporate and I need a fixed mass flux out

[Rob]

Try 2019R3, we've been doing a lot of work on multiphase over the last few releases.