Reduce diffusion error in a wavemaker case

GrivalszkiP · December 1, 2020, 15:47

Hi Foamers,

I have a flap wavemaker simulation.

From the results I can see that waves are smearing very fast, what differs from laboratory experimentents. How can I reduce this numerical diffusion error?

Tamas · December 3, 2020, 12:50

Hi Péter,

Try to use dynamic mesh refinement, or just play around the fvSchemes by setting less diffusive schemes.

GrivalszkiP · December 3, 2020, 16:31

Thank you for your reply!

Quote:

Originally Posted by Tamas

Try to use dynamic mesh refinement

I thought about it and I tried, but I could not solve it. I use the esi version of OF, I use the DynamicMeshDict to define motion or refinement. I tried to figure it out, but I could not solve to define both in one case. Do you have a solution for this? (OF v2006)

Quote:

Originally Posted by Tamas

play around the fvSchemes by setting less diffusive schemes.

I also tried, mostly with vanLeer and linear schemes, "Gauss interfaceCompression vanLeer" for div(phi,alpha) but no success. Any hint?

Anyway, I use k-Omega SST turbulence model with buoyancy correction by Larsen and Devolder (multiphaseStabilizedTurbulence)...

Tamas · December 4, 2020, 02:06

Hi!

Can you, please, upload a simple case to let me play with the setup?

GrivalszkiP · December 4, 2020, 04:02

Thank you, I'll send it with weTransfer link in e-mail through your website

December 1, 2020, 15:47	Reduce diffusion error in a wavemaker case	#1
GrivalszkiP Member Grivalszki Péter Join Date: Mar 2019 Location: Budapest, Hungary Posts: 39 Rep Power: 7	Hi Foamers, I have a flap wavemaker simulation. From the results I can see that waves are smearing very fast, what differs from laboratory experimentents. How can I reduce this numerical diffusion error?

December 3, 2020, 12:50		#2
Tamas New Member Tamas Egeresi Join Date: Nov 2014 Location: Budapest, Hungary Posts: 14 Rep Power: 11	Hi Péter, Try to use dynamic mesh refinement, or just play around the fvSchemes by setting less diffusive schemes. GrivalszkiP likes this. __________________ Tamas Egeresi Senior Hydraulics Engineer CFD Egeresi www.cfdegeresi.freecluster.eu

December 4, 2020, 02:06		#4
Tamas New Member Tamas Egeresi Join Date: Nov 2014 Location: Budapest, Hungary Posts: 14 Rep Power: 11	Hi! Can you, please, upload a simple case to let me play with the setup? GrivalszkiP likes this. __________________ Tamas Egeresi Senior Hydraulics Engineer CFD Egeresi www.cfdegeresi.freecluster.eu

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December 4, 2020, 04:02		#5
GrivalszkiP Member Grivalszki Péter Join Date: Mar 2019 Location: Budapest, Hungary Posts: 39 Rep Power: 7	Thank you, I'll send it with weTransfer link in e-mail through your website