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Defining a variable Viscosity ??

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Old   June 17, 2008, 04:41
Default Defining a variable Viscosity ??
  #1
MAB
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Any idea of how to define viscosity of water to be a funcions of x coordinate? I want to increase the viscosity after a specified distance in horizontal direction. Any suggestion 'll be appreciated. Thanking in advance. MAB
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Old   June 18, 2008, 18:08
Default Re: Defining a variable Viscosity ??
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Rogerio Fernandes Brito
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do you want to know how to make the expression or what expression to use?

For example: dynamic viscosity as a function of x coordinate times 2.

ownvisc(X)

A = 1.0 [Pa s] B = 1.0 [m]

ownvisc=(A*(2*(X/B)))

Make a CEL expression and edit this material on what you are working in!

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Old   June 19, 2008, 06:32
Default Re: Defining a variable Viscosity ??
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MAB
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Thanks Rogerio F.B. i will try this. what i exactly want is to increase the viscosity of water by 10 times after say x=20m where as total length along x-axis is 30m. i have tried it usin step function as step((x-20)/1m)*10*viscwater + actual viscosity of water but the solver didn't run ..each time it gave an error. any suggestion
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Old   June 19, 2008, 10:06
Default Re: Defining a variable Viscosity ??
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CycLone
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The solver will not allow the viscosity to change based on spatial coordinates make sense physically.

What are you physically trying to model? Why is the water viscosity changing at all?

-CycLone
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Old   June 20, 2008, 05:45
Default Re: Defining a variable Viscosity ??
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MAB
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Hi CycLone, I am modelling water waves on free surface. neer outlet i want to increase the viscosity of water so that the waves gets damped before approching the outlet, i want to do this to avoid refelection. (it has been easily done in starccm+) any further suggestion?(
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Old   July 10, 2008, 08:14
Default Re: Defining a variable Viscosity ??
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Jesse
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step((x/1[m]-20)*10*viscwater+actual visosity of water
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