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<div class="moz-cite-prefix">Hi,</div>
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<div class="moz-cite-prefix">What boundary conditions are you using?
How long do you integrate the equations at every Arnoldi
iteration? Around one tenth of the instability period should work.</div>
<div class="moz-cite-prefix">Do you get the unstable pair of
eigenvalues at all? Do the eigenvectors look physically correct?<br>
</div>
<div class="moz-cite-prefix">You may also want to use relatively
strict solver tolerances (around 10^-12 should work).</div>
<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix">Regards,</div>
<div class="moz-cite-prefix">Guillaume</div>
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<div class="moz-cite-prefix">On 2018-09-30 12:32,
<a class="moz-txt-link-abbreviated" href="mailto:nek5000-users@lists.mcs.anl.gov">nek5000-users@lists.mcs.anl.gov</a> wrote:<br>
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<div dir="ltr">Hi Nek,
<div> I am running ARNOLDI simulation case for a flow
over a 2D cylinder using ARPACK . My domain is [-50,50]
and Re=50. I have calculated base flow using SFD method.
While calculating Eigen values I have to run the restart
around 16-20 times to get an eigenvalues.txt file as an
output.</div>
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<div>Also the eigenvalues that are coming most of them has
zero rotation i.e., they are negative real value.
Suppose I want to have 30 eigenvalues as an output and I
am setting Krylov subspace as 90 then I am getting
around 20 of eigenvalues having zero rotation.</div>
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<div>Kindly help as I am stuck in it for long. Thanks in
advance.</div>
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<div>Regards,</div>
<div> Alok Mishra </div>
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<div> Aerospace Department IIT Kanpur</div>
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