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August 8, 2014, 15:36 |
CEL, CP, Pressure
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#1 |
Member
Mansoor Saleem
Join Date: Jun 2014
Posts: 31
Rep Power: 11 |
Hello
I am working with porous Domain for Adsobption process by using Zeolite and Water. For properties of Zeolite I have to use CEL for Cp and Enthalpy H, that CEL is pressure dependent. so when I emter the CEL i get an error that my CP is pressure dependent. Same is the case with Enthalpy. I need your help in this case. Thank you so much |
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August 9, 2014, 06:57 |
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#2 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
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Cp is defined as the "specific heat at constant pressure". Hence you cannot have it with varying pressure.
You are going to have to think of a physically realistic method of specifying the properties of this material. |
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August 9, 2014, 07:20 |
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#3 |
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Mansoor Saleem
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Thank you so much for reply, Ghorrocks
Is there any method to ignore this error, or anyother method to define properties like this. |
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August 9, 2014, 07:26 |
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#4 |
Super Moderator
Glenn Horrocks
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Sorry, on second thoughts you are right - the Cp can have values at any pressure, but it refers to the specific heat at constant pressure from the specified pressure. So yes, you should be able to define Cp as a function of pressure.
Please post some information about the material properties you are trying to apply, and your attempt at defining them so far. |
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August 9, 2014, 07:39 |
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#5 |
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Mansoor Saleem
Join Date: Jun 2014
Posts: 31
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I just have introduced a big expression for Cp which is a product of different variables and constant values. But because of Pressure its not working.
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August 9, 2014, 10:03 |
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#6 |
Member
Mansoor Saleem
Join Date: Jun 2014
Posts: 31
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Ghorrocks
I need help in this regard, can you give me any clue or any tutorial or other method?? Thanks |
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August 10, 2014, 06:46 |
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#7 | |
Super Moderator
Glenn Horrocks
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Quote:
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August 11, 2014, 04:45 |
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#8 |
Member
Mansoor Saleem
Join Date: Jun 2014
Posts: 31
Rep Power: 11 |
Ghorrocks
I am trying to insert, CP, Enthalpy and Density values.only CP and enthalpy are functions of pressure so they are creating problems. I have only made simple Expressions for that and inserted. |
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August 11, 2014, 07:52 |
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#9 |
Super Moderator
Glenn Horrocks
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Location: Sydney, Australia
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Please post your output file - please include the CEL expressions you are using and the error.
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August 11, 2014, 09:53 |
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#10 |
Senior Member
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The ANSYS CFX solver warns you if a pressure dependent specific heat capacity is supplied because the equation of state must also be consistent with such specific heat capacity. If such consistency is broken, the setup will be thermodynamically inconsistent
Please read the documentation section about "General Equation of State" Hope the above helps, |
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August 11, 2014, 11:12 |
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#11 |
Member
Mansoor Saleem
Join Date: Jun 2014
Posts: 31
Rep Power: 11 |
Thank you Ghorrocks and Opaque
I am excluding the pressure factor from CEL because of its negligible effect upon the Cp value. Now my CEL is working Thank you so much for help and cooperation. |
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