Learning Forum

[Loïc Féréol]

Hi Ansys community,

I want to compute a derivative using APDL. To be precise, I want to calculate the heating rate in post processing, i.e. the time derivative of Temperature. To do so, my idea is to use an Euler scheme using the temperature for a given time, the one before and the time step. Is there a way to do so (for an APDL beginner)?

Thank you,

[Erik Kostson]

 

Hi

 

One way of looking at this.

Perhaps look at post26 commands DERIV and prvar or plvar.

See the apdl command reference (in the help manual) for more info on these commands.

All the best

Erik

 

[Chandra Sekaran]

Yes, Post26 operations as Erik points out are best for doing this in MAPDL.

[Loïc Féréol]

Hi Erik and Chandra,

Thank you for your answers. I'm working on this right away !

Best, 

Loïc

[Erik Kostson]

A sample code that might help (variable 1 is time):

/POST26
nsol,2,2047,temp
deriv,3,2,1 
plvar,3

[Loïc Féréol]

Hi Erik and Chandra,

First, thank you for your advices that helped me a lot. For the moment, I can calculate the heating rate for each node and display it. Is there a command to display the quantity calculated on all the domain for a given time step (just like the temperature) ? I did not find such a command in the manual.

Best,