Hi all,

I am a beginner in CFX. My simulation involves big gradient in terms of temperature and pressure.

I would like to use the NASA format for the specification of specific heat capacity.

My material is air.

Do you know where I can find the NASA coefficients??

Thanks a lot in advance!!

U can touch (try) this!

http://www.nuigalway.ie/research/c3/chemthermo.html

Hi Cynthia,

The main components of Air (N2, O2, CO2) are all available in the CFX materials library with the corresponding NASA coefficients. The easiest way to create an AIR material with the NASA coefficients would be to create a fixed composition mixture from the components using the appropriate proportions of each.

-CycLone

Hi CyClone,

it is very interesting. I have done as you said, but then for Specific Heat Capacity I can select only Ideal Mixture. How Can I be sure that it is using the NASA format??

Thanks again!!!

Cyclone I have sort my doubt out. Thanks a lot!!you were very helpful! Thanks Rogerio...I had some problems with that software...but thanks for the quick response!

[Sal]

Dear cynthia,

Could you please explain how you did it?
I am simulating high speed flows, and in order to reproduce the correct experimental set up I have a very low static temperature (63K) at the inlet. Temperature range is between 60K to 280K throughout the domain. That means that the specific heat at constant pressure Cp has to be calculated properly as a function of temperature. As far as I know, the build-in NASA SP-273 database (CHEMKIN) has been calculated from a range of temperature above 200K/300K.

Any comment/suggestion about that?

Thanks in advance for your time.

Sal

[anon_a]

Dear Sal,

I have the same problem, the temperature is very low and
the Janaf model produces the wrong Cp. Did you succeed
in solving this?

S.P.