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K-episilon viscous model----Constant value.

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Old   August 13, 2001, 22:54
Default K-episilon viscous model----Constant value.
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Jie
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If I use K-episilon model, there are two values to set for boudary conditions: Turb. Kinetic Energy and Turb.dissipation Rate. Both of the default values are one ( constant value).

How will they influence the convergence?
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Old   August 14, 2001, 01:54
Default Re: K-episilon viscous model----Constant value.
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Armin Gips
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I always use the hydraulic diameter. I think it is more easy. Because you can estiamte the diameter from your geometry. And use for heavy turbulence 10 % turbulence intensity.

Armin
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Old   August 14, 2001, 07:28
Default Re: K-episilon viscous model----Constant value.
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Question Man.
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Hi all,

Yes, I use hydraulic diameter and turbulent intensity, mainly because I know the hydraulic diameter roughly.

Can anyne point me in the direction of papers dealing with boundary condition values for k and epsilon for pumps. I would like to see some typical values. Also, do my INITIAL condition k and epsilon radically effect the solution? I don't think they do (from testing), but I'm wondering if they should...at least in a significant way !! ?? Thanks.
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Old   August 16, 2001, 11:55
Default Re: K-episilon viscous model----Constant value.
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Jie
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But I use air as the fluid to calculate. And can you tell me haw much the values are?
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