Re: [ff3d-users] Problem with setting Boundary condition

[Juzar Thingna]

Hi Thomas,
Thanks for your prompt reply. Yes M ymin is on O for the simple geometry I'm using O and M are just the same. 

I'm trying the same with freemfem++ in order to check if there is any discrepancy in the result.

Cheers,
Juzar Thingna
Center for Computation Science and Engineering
National University of Singapore

On Sat, Apr 17, 2010 at 5:46 PM, Thomas Ward <address@hidden> wrote:

could it be because you are solving in O but the BC is defined on M?
are you sure M ymin is on O

I am not very familiar with ff3d so don't place too much faith on my suggestion.

good luck

Tom.

p.s. you may also try
getdp
freefem++ (from same group as ff3d)
fenics (python and c++, steeper learning curve)

they all have a similar philosophy to ff3d but development is more active

On 4/16/10, Juzar Thingna <address@hidden> wrote:
> Hello Everyone,
> Here is my input file:
>
> vector n=(70,90,70);
> vector a=(0,7,0);
> vector b=(20,37,20);
> scene S=pov("ferromagnet.pov");
> mesh M=structured(n,a,b);
> domain O =domain(S,inside(<1,0,0>));
> function L=36;
> function wb=0.37824;
> solve(w) in O by M
> krylov(type=bicg)
> {
> pde(w)
> div(L*grad(w))-w=0;
> dnu(w)= wb on M ymin;
> w=0 on M ymax;
> }
> mesh Z = tetrahedrize (O,M);
> save(medit,"w_fm",w,Z);
> save(medit,"w_fm",Z);
> save(raw,"w_fm.dat",w,M);
>
> I want to set the derivative of w along the y-direction to be equal to wb at
> ymin. I thought that setting dnu(w)=wb would do the trick, but apparently I
> don't get the value of the slope at ymin = wb.
> Please could someone guide me as in where I'm going wrong?
>
> The foll is my geometry file:
>
> box {<0,7,0>,<20,37,20> pigment{color rgb <1,0,0>}}
>
> Regards,
> Juzar Thingna
> Center for Computation Science and Engineering
> National University of Singapore
>