Explicit CEL variables
 

Hi everybody,

Anyone knows how can you use explicit variables in CEL? Or, is it possible to access variables or properties of previous time steps?

Thank you.

What do you mean by explicit variables? Example = 10[m/s]+2*Velocity is an explicit variable.

Can you access variables from previous time steps? This is not supported, but there is a unsupported method of doing it: see
https://www.cfd-online.com/Forums/cf...rans_loop.html
https://www.cfd-online.com/Forums/cf...-obtained.html

Note it is pretty unreliable and does not work in every case (that is why it is unsupported)

Alternately you can write some user fortran to do it.

adding to Glenn's question:

what are you trying to achieve that needs variables at previous timesteps?

I have a CEL expression that have to be evaluated with variables at the previous step. An example of this could be a temperature ON/OFF control.

It would be good if you described what you are actually trying to do because there usually is a better way of doing it.

But to answer your question: You cannot do temperature on/off control in a steady state simulation as it will never converge. If you want to do it in a transient simulation you can try the TRANS_LOOP approach or a user fortran routine, as previously suggested.