Learning Forum

[vsjay3]

Hi All,

This maybe a simple question but is important for me. In the material properties dialogue box (MPDB for short) of Fluent shown below, it shows a list of properties for the selected material. For example when I am modelling water, the material properties displayed for water are "density, specific heat capacity, thermal conductivity and viscosity".

Assuming that the relevant Fluent models have been selected, my question is:

are the material properties displayed in the MPDB the only properties of water that Fluent uses to perform the calculations or are there any extra hidden properties of water I cannot see in the MPDB that Fluent uses internally when calculating the solution.

In short, are the material properties displayed in the MPDB (for a specific material) the only properties of the selected material that Fluent takes into its calculation?

[DrAmine]

Only the properties which are required by the active models are shown. More properties will show up when the related models are activated.n

[vsjay3]

Thank you for your clear answer.nJust to confirm:nFor the liquids I use in my simulation model, only the density, specific heat capacity, thermal conductivity and viscosity properties are shown in the material properties dialogue box. So from your answer I take that density, specific heat capacity, thermal conductivity and viscosity are the only properties required for my simulation model.nThe reason I asked this is, I am currently creating a new fluid material in a User defined database for the same simulation model I'm running. So when creating a new fluid material, it will be correct if I only choose the density, specific heat capacity, thermal conductivity and viscosity properties from the available property list, correct ? (since they are the only properties shown in the material property dialogue box for my simulation model)nThank you very much!nn

[Rob]

You only need the properties that are shown in the panel, other properties are exposed as and when they're needed. We don't have any hidden extras in the materials panel. n

[vsjay3]

Thank you very much . Appreciate the advice.n

[YasserSelima]

thermal conductivity and heat capacity appear when you turn on energy equation ... viscosity is used in the viscous model, so it will appear in the properties unless you use inviscid n

[vsjay3]

Thank you Arrayfor your response.nI'm actually facing another issue. So I created custom fluid which is water-custom in my user defined database. However, when I try to delete that from the user defined database it gives the below error and I cannot delete it : nError: GENERAL-CAR-CDR: invalid argument [1]: improper listnError Object: #fnnI am not sure why.nAny help is appreciated.nThank you very much.n

[YasserSelima]

Don't delete it ... just don't use it in your setup.n

[vsjay3]

Thanks but may I know why I can't delete it?n

[YasserSelima]

I don't know ... GENERAL-CAR-CDR probably means some data are missing but I don't know what data !n

[vsjay3]

I see...I just thought that I couldn't delete it since it is the only material in the list...because if you add more materials you can delete those...but last one remaining cannot be deletedn

[Karthik R]

Hello,nYes, you need to have at least two materials (one solid and fluid) because the cell zones would use them as default values. Please don't delete everything under materials.nKarthikn