Hi Abhishek, You can try the following approach: 1. Have a 2D solution with u,v,c,p. 2. Prepare a session file with NumSteps = 0, and a homogeneous expansion in the z direction. 3. Add w to the expansion, variables boundary, etc. In initial conditions read u, v, c, p from file and set w to zero. 4. Run it, and you get a solution with u,v,w,c,p. Note: I am not sure you can successfully do this with HalfMode. SingleMode will work. Note 2: I am not sure this will be usable for the stability solver as baseflow (although I see no reason why?). I have not used the stability solver with an "active" scalar. I just played with the Rayleigh-Benard problem after David Moxley activated the ability to formulate BodyForce using the scalar value, about a year ago. Best, Stan On pią, 2018-10-26 at 11:31 +0100, Abhishek Kumar wrote:
Hi Stanislaw,
Thanks for the prompt reply.
1) Yes, you are correct. There is no effect of HomModesZ. It gives the same result with HomModesZ=1. 2) For the base flow, it works with <F VAR="u,v,p" FILE="bflow.fld" />. It doesn't ask for w.
But the problem comes when we add a scalar variable (for a problem like Rayleigh-Benard). In this case, I use <F VAR="u,v,c,p" FILE="base.fld" />, and it gives the following error:
Fatal : Level 0 assertion violation For half mode, expect 2D2C base flow.
I attached the session file. Can you comment on this issue?
With regards Abhishek
On Fri, Oct 26, 2018 at 8:29 AM Stanisław Gepner < sgepner@meil.pw.edu.pl> wrote:
Hi Abhishek,
Have you tried with setting this value to 1, and did the solver work and returned the same result?
1. Anyway, as far as I understand what is in SolverUtils/EquationSystem.cpp the value of HomModesZ is overwritten on initialization: 2 for SingleMode and 1 for HalfMode - so the value in the session file would seem redundant (Solver starts with this value removed).
2. Yes, AFAIK you need to have w in the BaseFlow section. It does not need to come from a file, you could do sth. like this:
<F VAR="u,v,p" FILE="bflow.fld" /> <E VAR="w" VALUE="0" />
So you can use a 2D solution with Fourier expansion.
Best, Stan Gepner
On czw, 2018-10-25 at 22:31 +0100, Abhishek Kumar wrote:
Hi,
I am trying to understand the session file "PPF_R15000_3D_VCS.xml." I have two confusion: 1) Since modeType is HalfMode than why "HomModesZ" is set to 2. I think this should be 1.
2) Since the base flow is 2D2C, then is it necessary to include variable "w" in the base flow?
In general, can we use a base flow generated from DNS which only have variables (uvp) in the session file having FIELDS = (uvwp)?
I would be highly thankful for the comments on this issue.
With regards Abhishek Kumar
---------------------------------------------------------------
-------------------- Abhishek Kumar Research Associate Applied Mathematics Research Centre Coventry University, Coventry CV1 5FB The United Kingdom
Email # ac7600@coventry.ac.uk, abhishek.kir@gmail.com ---------------------------------------------------------------
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