Concentration in the first Cell near the wall
 

Hi everyone,

I am using CFX-PRE to model an elbow, and i need to add a source term to this elbow. But it's depend on the concentration at the first cell near the wall.
How can i get this concentration in the cell near the wall so i can add my source term ?

Thanks for your answers

Is it a volume source term or a wall boundary source term?

it's a wall boundary source term

If you simply use the variable name it will give you the concentration at the first control volume. So if you want the average concentration at the control volume extending from the wall to half way to the first node you do not need to do anything special.

Or do you want the concentration from further in than the first control volume?

i have meshed my elbow, and i need to add a source term in a part of this elbow, this boundary source term is depending on the concentration of Oxygen near the wall.
but i don't know how can i get this concentration near the wall.

- have i to create a new variable named concentration then to create an expression

or i'm wrong and there's something easier

Have a look at the CFX documentation in the reference manual. It describes how to reference variables like concentration.