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-   -   Define mass flow boundary condition (http://www.cfd-online.com/Forums/openfoam-pre-processing/62180-define-mass-flow-boundary-condition.html)

tangd May 24, 2006 04:44

I am expected to do simulation
 
I am expected to do simulation by using sonicTurbFoam. But how to define the boundary condition becomes the problem. Since I have mass(m), Cp(T) and totalTemprature(Ttot) as input values.(Total temprature is a term with velocity integrated, similar to the definition of totalPressure p0 in OpenFOAM). I'm wondering how to assign these values within FoamX to initialize the boundary condition? Hoping to get answer soon! Thanks a lot!

tangd May 24, 2006 09:03

Sorry, the three input terms s
 
Sorry, the three input terms should be mass flow (dm/dt) [kg/s], Cp(T) and total Temprature(Ttot).

adamj July 12, 2006 09:03

Well, I cant help you directly
 
Well, I cant help you directly, I do not use TurboFoam.
I had the very same problem - given value of mass flow and total temperature at the inlet and I needed to develop a new
boundary condition for it. You may find it in AIAA Journal, Vol 44, No. 5, 2006

If you do not have it I would do this:
1. try to estimate approximately velocity on the inlet boundary
2. get Laval number from velocity and total temperature
3. get static temperature from velocity and mass flow
4. get total density from static density and laval number
5. get total pressure from total temperature and total density.
6. use ordinary total states inlet boundary conditions.

In any case I think you have to either implement new BC or face the uncertainty from estimating velocity in the inlet boundary,

Good luck


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