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Old   August 8, 2002, 09:11
Default Natural convection
  #1
JF
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Hi,

I need to simulate the flow due to the presence of a cold wall in a room. I have tried to simulate it but it doesn't converge. I have improved my mesh but it doesn't work.

Has anybody an advice on the question ?

Thanks a lot.

JF

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Old   August 8, 2002, 19:12
Default Re: Natural convection
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david
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Hello there, What kind of relation (density vs temp) did you use? It should converge (even for bigger time step), however, the motion of the airflow would be very slow if density diff is the main driving force in the room.

DC
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Old   August 8, 2002, 20:27
Default Re: Natural convection
  #3
Jin-Wook LEE
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For natural convection, you should be careful that,

1) enough grid should be embeded in the boundary layer

2) in general, unsteady calculation is needed for high Rayleigh number

Sincerely, Jinwook

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Old   August 10, 2002, 04:34
Default Re: Natural convection
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JF
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Hello,

Thank you for your answer. For the density, I use the Boussinesq relation(Define in material). I'm also not very sure of my viscous model, I use the K-eps Standard with an Enhancend Wall Treatement so I can simulate the Thermal Effect end the Buoyancy Effects.

JF
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Old   September 5, 2002, 12:48
Default Re: Natural convection
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sri
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Hi JF,

Body-force weighted scheme should help you.

sri
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