Simulation Air Stream in a System with out Outlet Boundary
 

Hi,

I would like to simulate a system which does not have any outlet. Infact, air as a media is sucked in my system through a fan, and again like a loop comes into the fan which probably should have a higher rotation speed. I would like to know how is the best model and boundary conditions for simulating this case in cfx?


regards,

I don't understand what you are trying to explain.

But the whole point of boundary conditions is you know the state of the fluid at that point, so you can specify it rather than modelling it. If you don't know the conditions at that point you cannot put a boundary condition there.

And a second point - if air goes into a domain and does not leave then air will accumulate in the domain. This will increase the temperature and/or pressure. It also means there is no steady state solution, so it must be a transient simulation.

Hi Ghorrocks,

First of all thank you because of your fast answer. You are absoloutly right. The fluid will accumulate and also its temperature and pressure will increase. Surely, it is a transient simulation. However, I do not understand whether it is possible to simulate a model with out Oulet boundary.

It sure is. Just give it a try.
I have performed calculations with a pump/fan with a closed outlet to determine the shut off head. This is possible in a transient calculation.