How can I make an interpolated function?
 

Dear All,

I am trying to make the heat transfer coefficient function, h(T), with respect to T. I have some sampled data sets as follows:

T:: 280 290 300 350 400

h(T):: 2 7 8 12 14

Here, I'd like to make an interpolated function of which name is 'myH.' Where can I setup this kind of function and how can I use it?

Many Thanks, Se-Hee

Re: How can I make an interpolated function?
 

Hi,

This is a CEL 1-d interpolation expression. It is described in the documentation.

Glenn Horrocks

Re: How can I make an interpolated function?
 

Dear Mr. Glenn,

Thanks for your comments. I have built my own interpolated function followed by your guide as follows:

1) In CFX-Pre, Create/User function

2) My function name is 'myHCoeff'

3) Interpolation, One dimensional

4) Input data set: Temperature .vs. heat transfer coefficient

5) OK

And when I use this function as boundary condition, how can I express the function? There were some errors to express my defined function when I try to use it. My expression was 'myHCoeff(T).' Is it incorrect?

Many thanks,

Se-Hee

Re: How can I make an interpolated function?
 

What were the errors?

Re: Error Message
 

The error message is as follows:

The variable 'T' referenced in parameter 'Heat Transfer Coefficient' in object '/Flow/Domain:Tank/Boundary:TankH/Boundary Conditions/Heat Transfer' does not have one of the required prefixes: phase or particle.

Thanks for your help.

Se-Hee

what is the prefixes: phase or particle?
 

As I mentioned in the above message, the error message was as follows:

The variable 'T' referenced in parameter 'Heat Transfer Coefficient' in object '/FLOW/DOMAIN:Tank/BOUNDARY:TankH/BOUNDARY CONDITIONS/HEAT TRANSFER' does not have one of the required prefixes: phase or particle.

Here, could anyone please explain 'phase or particle'? I've tried many ways for resolving my problem, but I am still stuck at this stage.

Se-Hee

Re: what is the prefixes: phase or particle?
 

If you have a multiphase flow, you need to add the phase/particle name before variables. Example:

Air Ideal Gas.Temperature

Maybe this is what the error message is referring to?

Re: solved this problem with input profile.
 

Considering your comments, I have solved this problem at last as follows:

1. making profile instead of table

2. retype the function -> myHCoeff.hval(WireAl.T)

where myHCoeff represents the function name of which I defined, hval represents the value of my function with reapect to temperature, and WireAl represents the material name of which I used in my simulation setup.

Thanks for all kind comments.

Se-Hee