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-   -   SPH boundary & discontinuity correction terms (https://www.cfd-online.com/Forums/main/104409-sph-boundary-discontinuity-correction-terms.html)

octtarek July 9, 2012 06:47

SPH boundary & discontinuity correction terms
 
I'm working on a CFD Matlab code using smoothing particle hydrodynamics (SPH) approach.

I have a great problem with the consistency at the boundaries & the discontinuities due to Shock waves. They make the code results totally wrong. I've tried to add terms for normalization & correction defined by (Liu) & (Chen) in the governing equations but I fail to get right answers.

Could anyone help me how to use the normalization & correction techniques in Navier-Stokes equations especially in discontinuities

dbarca July 27, 2012 06:15

What are you using to model your boundary conditions??

octtarek July 27, 2012 06:26

I used virtual exterior particles to mirror the fluid particles near the boundary. I didn't use boundary virtual particles.
Now I achieved the right results near the boundary. But in the wave discontinuity, I have an inaccuracy in result (represented in form of varying non-smooth results for a flow).

dbarca July 27, 2012 06:36

So you have used ghost particles...?

And are you also using Artificial Viscosity SPH?

octtarek July 27, 2012 06:38

Yes I used Monaghan Artificial Viscosity

dbarca July 27, 2012 06:46

As far as I know with AV SPH you will always encounter some problem with your results. If you want more quality and precision you should look for preciser variants of SPH like Riemann-SPH and delta-SPH...

octtarek July 27, 2012 08:05

OK I'll check & try that....many thanks


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