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-   -   Help on STAR-CD modelling helium injection in closed room. (http://www.cfd-online.com/Forums/main/1429-help-star-cd-modelling-helium-injection-closed-room.html)

Pavan Sharma October 21, 1999 04:14

Help on STAR-CD modelling helium injection in closed room.
 
I am trying to model a scenario of helium injection in a closed room. I am a new user to STAR-CD. I have tried helium as a Scaler. I have used inflow boundary condition with finite Z velocity component. The code warns about the imbalance in mass conservation in absence of outflow boundary condition. Can somebody, a reguler user of STAR-CD help me teaching multicomponent gas distribution studies in a closed room. Alternatively, is any other freely availbale tool exist in this regard.

Pavan Sharma 411,HALL-7 RSD, BARC Trombay, Mumbai India

pksharma@magnum.barc.ernet.in

Robert Bland October 21, 1999 12:02

Re: Help on STAR-CD modelling helium injection in closed room.
 
Your approach will not work steady state as you will eventually pressurise the room to an infinite pressure as you are continually adding mass. That is why the code is warning you about a mass imbalance. You will have to run this as a transient with physically realistic values for the injection rates and timescales. I am assuming that you are trying to match an experiment so this would give you suitable values. Otherwise you will have to devise credible values yourself.

An alternative to the inlet boundary would be a scalar mass source but this will obviously not solve the basic physical problem of trying to run this type of problem steady state.

Pavan Sharma October 22, 1999 06:13

Re: Help on STAR-CD modelling helium injection in closed room.
 
Thanks Mr. Robert Bland

I have formulated it as a transient problem it self. I could solve the problem using proper equation of state which is required for the compessible formulation. Please give your email add. also.

Pavan


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