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Old   August 12, 2016, 07:09
Default Error in defining expression
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Aja
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Hi,

I am defining an expression, but i have a error as follows:



Why does this happen?

Thanks.

Last edited by aja1345; August 16, 2016 at 08:06.
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Old   August 12, 2016, 07:24
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What does this mean? )(
try )*( multiplication if this is what you want?
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Old   August 12, 2016, 07:34
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Quote:
Originally Posted by urosgrivc View Post
What does this mean? )(
try )*( multiplication if this is what you want?
Yes!!! Thanks
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Old   August 12, 2016, 09:10
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Hi,

Why does the following error happen?




I want to define gas constant of air.

Last edited by aja1345; August 16, 2016 at 08:05.
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Old   August 12, 2016, 10:07
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Why does unit of the following expression equal to Kg^2 m s^-5 K^-2?

volumeInt(((Thermal Conductivity/(Temperature)^2)*((1/(Density*(R/(M air))))*(Pressure.Gradient X)^2+(1/(Density*(R/M air)))*(Pressure.Gradient Y)^2+(1/(Density*(R/M air)))*(Pressure.Gradient Z)^2)))@Rotary



R=gas constant


According to above, Unit of Volume integral should be equal to W/ K or kg m^2/S^-3 K^-1 . I assumed fluid as ideal gas presently. therefore>>>>> P=Ro*R*T

T=P/(RO*T)

.........


Thanks.

Last edited by aja1345; August 16, 2016 at 08:07.
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Old   August 14, 2016, 14:08
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I dont think that [Kj] means enithing.
definitly not with smal j

I am asking the experts now-> (is kilo(k) , mega(M) and other prefixes suported instead of multipliers) as I havent tried it out myself.

Joul=J should work but than, for Kilo you should multiply it by 1000.
so you would end up with [J kg^-1 K^-1]*1000
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Old   August 14, 2016, 19:31
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Yes, CFX supports the SI unit system with prefixes. But you have to get it correct, as urosgrivc states. Joule is J and kilo prefix is k, so the unit if kJ.
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Old   August 15, 2016, 07:15
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Thanks.

What is your suggestion about defining expression?

I am grateful that guide me about this case.

Last edited by aja1345; August 16, 2016 at 08:08.
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Old   August 15, 2016, 07:41
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I think the temperature gradient functions work in CFD-Post. Have a look in the CFX reference manual for a description of the available variables and functions you can apply to them.

Also the temperature gradient variables will be available under the puzzlingly titled "..." button for plotting on surfaces, vectors etc.
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Old   August 15, 2016, 15:28
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Quote:
Originally Posted by ghorrocks View Post
Also the temperature gradient variables will be available under the puzzlingly titled "..." button for plotting on surfaces, vectors etc.
Thanks.

I don't understand this your statement. Can you explain more?

What is "..." button?
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Old   August 15, 2016, 15:42
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Insert an User Defined Variable, for the method select Gradient, and select Temperature for the variable. CFD-Post will create the Temperature.Gradient variable.

You can then use it as needed.
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