Numerical schemes for grad and div
 

Hello Foamers,

I have a question to some schemes in OpenFOAM.


grad-Scheme
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

What is the differences between
Its clear that I use a limiter for the grad schemes. But does that mean, that the change of U^{n-1} to U^n is limited? Is my interpretation correct?

div-Scheme
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Whats the difference between

I think the first scalar is for the limiter. 1=full limiter 0=non limiter. The values after that are bouding parameters? so that the variable Z is bounded between [0-1] ? is that correct? And the differences between both?


Any suggestion would be very nice.
Regard
Tobi

hi
can anyone answer to these questions?
thanks.

Hi all,

results of different schemes can be found on my homepage (its unfortunatelly german but with graphics)

http://www.holzmann-cfd.de/index.php...rische-schemen

Hi Tobias,

Nice graphics:) Just a quick question from a non-German speaking person. Is it a pure advection problem, which you have been solving?

At least with a quick view on a couple of the cases, it seems that you are only changing the divergence scheme.

Thanks,

Niels

Niels, indeed the site states pure convection ("reine Konvektion").

Hi,

yes I am only changing the div schemes to get influence of konvection influence ... "there is no diffusivity". That s necessary to get see what influence the different schemes are make in the equations.

I found the following paper that includes some other results along the same lines as Tobi. The paper includes the step function and two other shapes.

http://powerlab.fsb.hr/ped/kturbo/Op...GammaPaper.pdf

Dan