CFD Online Discussion Forums - Vorticity generation in oodles

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)

- OpenFOAM Running, Solving & CFD (https://www.cfd-online.com/Forums/openfoam-solving/)

- - Vorticity generation in oodles (https://www.cfd-online.com/Forums/openfoam-solving/59393-vorticity-generation-oodles.html)

Hi guys I'm studing the effec

Hi guys
I'm studing the effect of adding body force(F) to oodles solver.
Where F is exponential function:
F= A*exp(B*(x^2+y^2+z^2)
that i force it to my case geometry center for only 1 iteration . A & B are constants.
My study case is a channel with uniform inlet velocity(=10m/s).and the sides are symmetryplane.
......
so i changed oodles solver:

if (momentumPredictor)
{
solve(UEqn == -fvc::grad(p)+Fcoefficient*F);

}

Where Fcoefficient changes between 0&1 for iteration control.so it is 1 for only 1 iteration

You can see some figures that shows the vorticty variation with time changing in flow :
: http://www.cfd-online.com/OpenFOAM_D...your_image.gif
: http://www.cfd-online.com/OpenFOAM_D...your_image.gif
: http://www.cfd-online.com/OpenFOAM_D...your_image.gif
: http://www.cfd-online.com/OpenFOAM_D...your_image.gif
: http://www.cfd-online.com/OpenFOAM_D...your_image.gif
: http://www.cfd-online.com/OpenFOAM_D...your_image.gif
How i can explan the variation of vorticity distribution by time changing?
Can you explan me more detailes in this field ?

Have a nice weekend
Marhamat

sorry for duplicate sending :

Sorry again for disturbing you

Sorry again for disturbing you. )-:
I promise to be a good boy and not to do it again.(-;

http://www.cfd-online.com/OpenFOAM_D...ges/1/5533.gif

Regards
Marhamat

Hi everybody I hope that some

Hi everybody
I hope that somebody help me in this problem .
I repeated the noted steps in icoFoam solver.
In first iteration after adding F the figure of vorticity is like to fig of vorticity in oodles solver but in this solver the spots of vorticity don't increase by time increasing in flow and we can see difusion of vorticity .
http://www.cfd-online.com/OpenFOAM_D...ges/1/5624.jpg
http://www.cfd-online.com/OpenFOAM_D...ges/1/5625.jpg
http://www.cfd-online.com/OpenFOAM_D...ges/1/5626.jpg
I must note that when velocity is zero in first iteration the figure of vorticity is different.
How i can justify these differences?
http://www.cfd-online.com/OpenFOAM_D...ges/1/5627.jpg
Best Regards
Marhamat