Hello all!

I've been trying to search for a method in Star to time-average transient results for unsteady flows. I went through the archives and still reading after a few hours. Maybe this has been explained before but if you don't mind, kindly tell me how do this time-averaging of transient results this time. Is this available in GUI? If not, do tell.

This is an example of prostar macro which I got from Paco who works for the support team in Nürnberg.


The example I was working with had 107 time steps (beginning
from
iteration 2 and increments of 2):

!First loading the pstt file!
trload,druck.pstt,nomvgr,,c
store,iter,2
!We could equally use the command getc, but if one does so,
all the postregisters are cleared.
oper, getc, su, 1
oper, getc, sv, 2
oper, getc, sw, 3
!Postregisters 1 to 3 are devoted to stored velocity
components (in this example). We
!then use postregisters 4 to 6 to store the sum of the
different iterations.
oper, copy, 1, 4
oper, copy, 2, 5
oper, copy, 3, 6
!Here we begin the loop for reading the remaining of
iterations
*define, noexe
*set, increm, 2, 2
store, iter, increm
oper, getc, su, 1
oper, getc, sv, 2
oper, getc, sw, 3
oper, add, 1, 4, 4
oper, add, 2, 5, 5
oper, add, 3, 6, 6
*end
*loop, 1, 107, 1
!In our example the number of time steps stored were 107
oper, sdiv, 107, 4, 4
oper, sdiv, 107, 5, 5
oper, sdiv, 107, 6, 6
oper, inverse, 4, 4
oper, inverse, 5, 5
oper, inverse, 6, 6

Thank you very much for your prompt response. I really needed something like this urgently.

I will modify this macro and inform you of my progress. I suppose the end-product of this macro is one post file? Can I save it with a different name?

It may be possible to activate the les averaging option (*.lesc files) for your case. I know you can do this with DES in 315.

I am not sure of the exact process, but I would say

Copy your old problem file

Turn on the les model with averaging and write the problem file (you may get some warnings regarding discretisation etc.).

Check the differences, I suspect one of them will be the flag to activate averaging. You will have to make a edit by hand of the problem file for every case you want to do averaging on.

Try these settings on a small model.

It is worth a try.

Steve

Interesting! Will try! At the moment too much work too little time...

Thanks for the idea!

you can do the avereging in the postdat soubroutine and compute any variable you want!