Ex#3 - Integrated Quantity Boundary Conditions
 

Hi everybody!

I´m a CFX beginner and I have a model quite similar to the example 3 shown in user function examples at printable books. But it doesn´t clarify my questions on how to get fluid properties like temperature and density from a position (outlet Boundary Condition) and insert it into another position. I mean, I got a room wich is been cooled (transient) so I need to get an average temperature at the outlet surface and give it as a temperature at the inlet boundary condition. So the fluid goes out from domain, after that is cooled and return to domain. Does anyone know how to build that subroutine shown in that example? How can I do it without using User Function? What is the best choice to me?

Thanks!

Re: Ex#3 - Integrated Quantity Boundary Conditions
 

Hi Vinicius,

You can make your inlet a function of your outlet by adding the appropriate integral CEL function. For instance, if you want the inlet temperature to be 10 percent lower than the mass averaged temperature at an outlet boundary named "Exit", simply use the following expression for the inlet temperature:

massFlowAve(T)@Exit * 0.10

Regards, Robin

Re: Ex#3 - Integrated Quantity Boundary Conditions
 

Thanks a lot Robin!!

I´ll try it!

Best regards Vinicius

Re: Ex#3 - Integrated Quantity Boundary Conditions
 

Hi Robin, This function is very interesting! Where can I get more informations about this kind of functions? Did we have this in the CFX Printable books? Regards, Lucio

Re: Ex#3 - Integrated Quantity Boundary Conditions
 

Yes, look in the documentation for the CFX Expression Language. It covers all the integrated quantity functions available in the flow solver and CFX-Post.

Neale