[typhoon1010]

I would like to ask a question.

Can I set the value of fluid properties what I want for obtain prandtl and rayleigh number.

I am working natural convection. I added my working.

Rayleigh 10^7 and Prandtl 1. I need to real fluid properties and values must be suitable my working.

When I try to, wall temperature differences is very high. Then fluent does not work.

How I set the value of fluid properties.(cp,k,mü,beta, ro vs.) Which fluid?

Thank you in advance.

[LuckyTran]

You can arbitrarily set the fluid properties to be pretty much anything. They are in the materials pane. Just edit whatever is already there (the default is air). You can leave the name as-is or rename it to your "custom fluid."

[typhoon1010]

Thank you for your answer. I mean I do not want to standart conditions as 20 or 80 degrees celcius air properties.

Can I design for example
ro=1000
cp=11030
dynamic viscosity=0.001
k=11.03
beta=10^-5

This values provide prandtl 1 and rayleigh 10^7

Is it possible?

[LuckyTran]

Yes. You can put in anything. Just keep track of the units to make sure you get the Reynolds and Rayleigh numbers that you want, because Fluent is a dimensional solver.

[typhoon1010]

ok I understand. Thank you your answer.

Unfortunately, I am obliged to use thermodynamic table for validate model.

I tryed saturated water vapor for prandtl 1 with boussinesq approxiamation in fluent. Result is very bad.

Can you suggest me fluid or other way this problem?

Best regards.