<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><div><div>Hi Neks,<br></div><div><br></div><div>I was doing an FSI problem on Naca0012. I had already validated an FSI problem on a cylinder. Here I confued a bit with BC's applied thourgh usr file.</div><div><br></div><div>Here is an example of the BCs on the cylinder from your examples</div></div><div><br></div><div>c-----------------------------------------------------------------------<br> subroutine userbc (ix,iy,iz,f,eg)<br> include 'SIZE'<br> include 'TOTAL'<br> include 'NEKUSE'<br><br> integer e,eg,f<br><br> common /c_mybc/ umesh<span style="height: 18; width: 34; padding: 9px 34px 9px 0; background: url('https://webmail.ec-nantes.fr/service/zimlet/com_zimbra_ymemoticons/img/14.gif') no-repeat 0 50%;" title="X( - en colère" data-mce-style="height: 18; width: 34; padding: 9px 34px 9px 0; background: url('https://webmail.ec-nantes.fr/service/zimlet/com_zimbra_ymemoticons/img/14.gif') no-repeat 0 50%;"><span style="visibility: hidden;" data-mce-style="visibility: hidden;"></span></span>lx1,ly1,lz1,lelt)<br> $ , umeshy(lx1,ly1,lz1,lelt)<br> $ , umeshz(lx1,ly1,lz1,lelt)<br><br><br> if (x .lt. -1.1) then<br> ux=1<br> uy=0.<br> uz=0.<br> else<br> e = gllel(eg)<br> ux = umesh<span style="height: 18; width: 34; padding: 9px 34px 9px 0; background: url('https://webmail.ec-nantes.fr/service/zimlet/com_zimbra_ymemoticons/img/14.gif') no-repeat 0 50%;" title="X( - en colère" data-mce-style="height: 18; width: 34; padding: 9px 34px 9px 0; background: url('https://webmail.ec-nantes.fr/service/zimlet/com_zimbra_ymemoticons/img/14.gif') no-repeat 0 50%;"><span style="visibility: hidden;" data-mce-style="visibility: hidden;"></span></span>ix,iy,iz,e)<br> uy = umeshy(ix,iy,iz,e)<br> uz = umeshz(ix,iy,iz,e)<br> endif<br><br> return<br> end<br>c-----------------------------------------------------------------------<br></div><div><br></div><div><br></div><div><br></div><div>My doubt is why there is an else condition in the BC's.<br></div><div><br></div><div>Is it something related with the initial perturbation?</div><div>When I apply this BC on NACA0012 I get some strange boundary layer flow.<br></div><div><br></div><div>Could you please help me to solve this?<br></div><div><br></div><div><br></div><div>Thank you have a nice day<br></div><div><br></div><div><br></div><div>Sijo</div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div></div></div></body></html>