Learning Forum

[hsr200]

Hi.

I'm currently simulating flow in nozzle. And fluid is JP-10. (It is not in REFPROP.)

Because I need JP-10's property, so I generate RGP Table of water and change each property of JP-10.

When I use JP-10 RGP Table in Fluent, laminar model, density value in Fluent result are not match my JP-10 data.

For example my JP-10 data at T=323 K and P=0.4 MPa, density must be in 882~876 kg/m^3

But result in Fluent at same temperature and pressure, density is in 789~780 kg.m^3. normally this is 450~460 K value at 0.4 MPa.

And use water RGP table and simulate water in same condition, water density value in Fluent result is same in REFPROP data.

So I want to know why it is happen. is it related other table or layout?

And I have another question about RGP table layout.

In the top of the table, there are 'PARAM'. In water RGP table, it indicates 25.

I set this same value when make JP-10 table. So is 'PARAM' value are different in fluid?

Thanks.

[Surya Deb]

Hello,
How do you generate the RGP table? Also, I am not sure when you say you "change each property of JP-10".
How do you do this after the RGP table for water has been generated? Do you go through the entire table?
Regards SD

[hsr200]

Hi SD
I use Fluent beta feature manual and generate RGP table. (The name of chapter might be "Creating RGP Files")
I generate water RGP table, and change it's value.
In water table, there are tables like volume, specific heat, viscosity, thermal conductivity and so on.
Each table consist p-T relation.
I changed each table value. for example, In volume table,changed water's volume to JP-10's volume. and other tables did same like volume case.
I use text file format to change each contents.
Thanks

[Amine Ben Hadj Ali]

The Fluent beta features does explain the process and if you have access or your supervisor has access to Customer Portal we wrote a couple of solution related to the generation of RGP tables.
I won't change anything in the table: this will make the thermochemical properties inconsistent with one another.
What is your goal in changing?

[hsr200]

Hi Amine
My goal is that just simulate flow JP-10 fluid in nozzle.
And JP-10 property data is not exist in REFPROP.

[Amine Ben Hadj Ali]

That is not an excuse to start manipulating the material properties which require to be consistent. What about sticking to Real Gas CUEOS? Details about the table can be found in Ansys CFX Guides: you can tune on your own responsibility.

[hsr200]

Ok
And may I ask what chapter in CFX Guides?

[Amine Ben Hadj Ali]

It is mentioned in the Fluent Beta Feature Guide: a link is there.

[hsr200]

Is it right "12.6 Real Gas Property(RGP) File contents" in CFX guide?
(I'm sorry to bother you.)

[Amine Ben Hadj Ali]

Yes.

[hsr200]

Um... I already see that chapter and make same RGP file format like 12.7.1.1 and 12.7.1.2.
Is there another major consideration when make RGP file like 12.7.1.1 format?
and is there limitation number of property?