Re: [ff3d-users] Navier-Stokes problem

[Stephane Del Pino]

Hello Tomas.

I noticed something wrong in your ff3d file:

        double eps = 1000;
        function P  = eps*one(<1,0,0>)+1
// ... then ...
         double fx = int[M](ki/eps*u);
         double fy = int[M](ki/eps*v);
         double fz = int[M](ki/eps*w);

The problem is that in my mind, eps is something small and P is defined using 
1/eps so the force here is not evaluated correctly. I suggest:

        double eps = 1E-4;
        function P  = 1/eps*one(<1,0,0>)+1
// ... then keep ...
         double fx = int[M](ki/eps*u);
         double fy = int[M](ki/eps*v);
         double fz = int[M](ki/eps*w);

I have run you example for a few iterations, and I get for instance
<#i=8
<#Fx=-0.378171
<#Fy=2.7602e-05
<#Fz=-0.0644279

Is it more what you expect?

Best regards,
Stéphane.