[Nek5000-users] Regarding base velocity (Mesh deformation)

[nek5000-users at lists.mcs.anl.gov]

Hi Neks, 
I had sent you a detailed problem regarding base velocity (mesh motion and mesh deformation) in the morning unfortunately i have not get any replay yet . I think you guys are busy otherwise you guys are very resposive. I appreciate that. Even though I investigated my problem and I think i found where actually the problem is even though I still need some clarifications in that. 

The problem were in the boundary conditions since there are two type of B.Cs Homogenous (zero on all non- interior boundary faces ) and Inhomogenous( 1 at moving boundary faces). When i was trying on 2D there were no problem with B.Cs. But when i i tried my 3D mesh where a new B.C has come which is called SYMMETRY b.c. I imposed the SYM conditions on the horizontal walls of the fluid domain (not on the object) and also the exterior to the fluid domain on 3rd dimension.(3D means i put a thinkess as size of one element, which makes my foil case into 3D) As a result, for one element near the moving body, I have a m.v condition, SYM conditon on the exterior of the fluid domain in 3rd direction (lets say Z direction, so SYM on both sides) and E on the interior of the fluid domain. 

So the condition I gave is given below : 


m1 = -1. 
y0 = 0.0 

nface = 2*ndim 


do e=1,nelv 
do f=1,nface 

c Set Dirichlet for mesh velocity on all boundaries 

if (cbc(f,e,1).ne.'E ') call facev(msk,e,f,y0,nx1,ny1,nz1) 


c Inhomogeneous Dirichlet on foil only 


if (cbc(f,e,1).eq.'mv '.or. cbc(f,e,1).eq.'SYM ') then 
if((ym1(1,1,f,e).lt.6.0).and.(ym1(1,1,f,e).gt.-6.0)) then !! where my domain +6 to -6 in Y direction and 0 to 0.1 in Z direction and -8 to 8 in X direction 
call facev(tmp,e,f,m1,nx1,ny1,nz1) 
endif 
endif 


enddo 
enddo 


Now I get a better basev (the values ranges between 0 and 1.2 before it was less than zero). But still I am getting a value which is slightly greater than 1.0 which is not good. So could you please tell me what should I do in this case, to have a nice smoothing velocity to all the mesh. 

Thanks with Regards 

Sijo GEORGE 
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