[Nek5000-users] Nek5000 pertubation mode

[Antonios Monokrousos]

Dear Paul,
I tested the new version also with my case (blasius BL) and it works
fine (with de-aliasing)!
Many thanks!
Antonios

Paul Fischer wrote:
> 
> 
> Dear Antonios,
> 
> If you can try the current version of the svn repo,
> the perturbation code should now work with dealiasing
> turned on.
> 
> Moreover, you can automatically turn off the base-flow
> evolution by setting the number of perturbation modes
> (p31 in the .rea file) to be < 0.  Thus, p31=-1 would
> give one perturbation mode, no base flow evolution.
> The base flow would be defined, e.g., in the useric.
> 
> I include an example case in the attached tarfile,
> Orr-Sommerfeld evolution.
> 
> Paul
> 
> 
> On Wed, 3 Jun 2009, Antonios Monokrousos wrote:
> 
>> Dear Paul,
>> I finally found what the problem with my case was. It was the
>> de-aliasing. The problem appears first in the subroutine advabp (file
>> perturb.f) where subroutine convop is called (file navier1.f). It seems
>> that de-aliasing is not working for the pertubation/linear mode (?) When
>> I deactivate the de-aliasing (from the rea file) the result looks
>> correct.
>> I tested it also with channel flow and it was the same problem: In
>> pertubation mode, with de-aliasing a forcing appears in a few specific
>> elements. I haven't been able to understand exactly why this happens but
>> I suspect it has to do with the size of the arrays.
>> Best regards
>> Antonios
>>
>>
>> --