<html>
  <head>
    <meta content="text/html; charset=windows-1252"
      http-equiv="Content-Type">
  </head>
  <body bgcolor="#FFFFFF" text="#000000">
    <p>Thanks very much Paul.</p>
    <p><br>
    </p>
    <p>Sincerely,<br>
      NN.<br>
    </p>
    <br>
    <div class="moz-cite-prefix">On Monday 06 November 2017 01:30 PM,
      <a class="moz-txt-link-abbreviated" href="mailto:nek5000-users@lists.mcs.anl.gov">nek5000-users@lists.mcs.anl.gov</a> wrote:<br>
    </div>
    <blockquote
      cite="mid:mailman.1993.1509971449.19102.nek5000-users@lists.mcs.anl.gov"
      type="cite">
      <meta http-equiv="Content-Type" content="text/html;
        charset=windows-1252">
      <style type="text/css" style="display:none;"><!-- P {margin-top:0;margin-bottom:0;} --></style>
      <div id="divtagdefaultwrapper"
style="font-size:12pt;color:#000000;font-family:Calibri,Helvetica,sans-serif;"
        dir="ltr">
        <p><br>
        </p>
        <p>Dear NN,</p>
        <p><br>
        </p>
        <p>If your flow is turbulent the answer is definitely Yes (they
          will be different) because of the standard sensitivity to
          initial condition concerns.</p>
        <p><br>
        </p>
        <p>Despite this, both schemes are O(dt^k) accurate, meaning
           that as dt-->0, the error goes to _zero_ as dt^k, where
          k=Torder is the prescribed temporal order.   Since the error
          goes to zero, both will deliver the same answer provided that
          the physical solution is stable and has an attractor.  
          [Understanding when such conditions prevail is often a
          challenge.]</p>
        <p><br>
        </p>
        <p>Paul</p>
        <p><br>
        </p>
      </div>
      <hr style="display:inline-block;width:98%" tabindex="-1">
      <div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt"
          color="#000000" face="Calibri, sans-serif"><b>From:</b>
          Nek5000-users <a class="moz-txt-link-rfc2396E" href="mailto:nek5000-users-bounces@lists.mcs.anl.gov"><nek5000-users-bounces@lists.mcs.anl.gov></a>
          on behalf of <a class="moz-txt-link-abbreviated" href="mailto:nek5000-users@lists.mcs.anl.gov">nek5000-users@lists.mcs.anl.gov</a>
          <a class="moz-txt-link-rfc2396E" href="mailto:nek5000-users@lists.mcs.anl.gov"><nek5000-users@lists.mcs.anl.gov></a><br>
          <b>Sent:</b> Monday, November 6, 2017 6:13:11 AM<br>
          <b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:nek5000-users@lists.mcs.anl.gov">nek5000-users@lists.mcs.anl.gov</a><br>
          <b>Subject:</b> [Nek5000-users] IFCHAR option in rea file</font>
        <div> </div>
      </div>
      <div class="BodyFragment"><font size="2"><span
            style="font-size:10pt;">
            <div class="PlainText">Hello,<br>
              <br>
                I have been using IFCHAR = TRUE in my simulations. The
              CFL number is <br>
              around<br>
              1.2 and the computations appear to go on nicely. I would
              like to know<br>
              if the flow field computed using IFCHAR=TRUE option is
              different than the<br>
              one obtained with IFCHAR=FALSE (albeit with smaller dt)?
              If yes, can the <br>
              difference<br>
              be significant?<br>
              <br>
              Many thanks,<br>
              NN<br>
              <br>
              _______________________________________________<br>
              Nek5000-users mailing list<br>
              <a class="moz-txt-link-abbreviated" href="mailto:Nek5000-users@lists.mcs.anl.gov">Nek5000-users@lists.mcs.anl.gov</a><br>
              <a moz-do-not-send="true"
                href="https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users">https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users</a><br>
            </div>
          </span></font></div>
      <br>
      <fieldset class="mimeAttachmentHeader"></fieldset>
      <br>
      <pre wrap="">_______________________________________________
Nek5000-users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Nek5000-users@lists.mcs.anl.gov">Nek5000-users@lists.mcs.anl.gov</a>
<a class="moz-txt-link-freetext" href="https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users">https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users</a>
</pre>
    </blockquote>
    <br>
  </body>
</html>