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-   -   Inlet mass flow ( to Glenn) (http://www.cfd-online.com/Forums/cfx/26125-inlet-mass-flow-glenn.html)

Manu July 20, 2008 10:14

Inlet mass flow ( to Glenn)
 
Hi Glenn,

I am simulating a case of pool fire. When i am putting real mass flow in than the flame seems to be unrealistic and the flame is running away from its source though it works prettily when a mass flow is reduced by 100 times than i get a good shape of flame. I am not able to understand why did it happen? Should i go for a profile shape at inlet or some other idea would be a great help. Thanks in advance!

Regards

Manu

Glenn Horrocks July 20, 2008 18:50

Re: Inlet mass flow ( to Glenn)
 
Hi,

We will need a lot more detail about what you are modelling before we can help.

Glenn Horrocks

Manu July 21, 2008 05:08

Re: Inlet mass flow ( to Glenn)
 
Hi Glenn, The inlet mass flow i am prescribing is the measured burning rate of my fuel. Now i have opening everywhere except bottom wall where the pan is kept and pan wall which are no slip adiabatic walls. Now i am using k- epsilon turbulence model, eddy dissipation (single step chemistry) combustion model, discrete radiation transfer and Magnussen soot models. Now the problem is when i start my simulation (lets say steady state and without soot model) with real mass flow, i get a flame far away from inlet ( like a diffuser ). When i reduce this inlet mass flow by 100 times i get a good conical shape flame ( thats what i can expect from single step chemistry). What should i understand from this? Is this real mass flow is numerically unphysical? Please help me if you can.

Regards

Manu

Glenn Horrocks July 21, 2008 22:26

Re: Inlet mass flow ( to Glenn)
 
Hi,

Sounds like you need more detailed assistance than is possible on the forum. I would contact your CFX support representative.

Glenn Horrocks


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