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<p style="margin-top:0;margin-bottom:0">Dear Zhenrong,</p>
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<p style="margin-top:0;margin-bottom:0">Please send me your case files off-list, along with an explanation of how you start the case that re-laminarizes.</p>
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<p style="margin-top:0;margin-bottom:0">I'll try to sort this out.</p>
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<p style="margin-top:0;margin-bottom:0">Thanks!</p>
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<p style="margin-top:0;margin-bottom:0">Paul</p>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Nek5000-users <nek5000-users-bounces@lists.mcs.anl.gov> on behalf of nek5000-users@lists.mcs.anl.gov <nek5000-users@lists.mcs.anl.gov><br>
<b>Sent:</b> Friday, March 16, 2018 3:22:07 AM<br>
<b>To:</b> nek5000-users@lists.mcs.anl.gov<br>
<b>Subject:</b> [Nek5000-users] Small random perturbations</font>
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<div>Hello everyone<br>
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<div>I have been troubled by the exactly same problem with Ali for the last two months with the turbulent channel case. When I increase elements, the flow is laminarized even though the Re is quite big (10000). I tried many different ways. Even added a constant
random forcing, but the disturbance just disappear. (because the disturbance shape is not the same as that in linear stability theory, it is possible that the disturbance just decay. )<br>
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<div>How I finally solve this problem is running a coarse mesh calculation first, and then interpolating the result to fine mesh. Then I got a sustaining turbulence and the result is quite satisfying. I hope this could solve Ali's problem.<br>
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<div>However, I still cannot understand why increasing resolution would laminarize flow. hoping someone else could explain the problem.<br>
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<div>Regards<br>
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<div>Bien cordialement<br>
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<div>Zhenrong JING<br>
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<div>Doctorant (Doctor Candidate)<br>
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<div>LHEEA</div>
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<div>Ecole Centrale de Nantes<br>
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<div><span class="x__Xbe">1 Rue de la Noë, 44321 Nantes, France<br>
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