How does SPH resolve the wall with regards to turbulence?

Asalih3d · November 2019

Hey

How does DualSPHysics actually calculate the shear stresses at walls etc. ? As far as I know there are no models for the wall in DualSPHysics, and maybe not for SPH in general?

I just wondered since we have a course about turbulence right now and in typical CFD theory this concept seems to be of high importance, while I don't think I have seen too much of it in SPH.

But I am of course open to be corrected :-)

Kind regards

JOJO · November 2019

i think it is very hard for SPH to model the boundary layer. so, if you talking about the shear stresses of the fluid below the boundary layer ,maybe the answer is no.

But maybe we can focus on the hybrid method such as, SPH-FVM

And for the shear stresses of wall, it maybe possible. SPH-DEM, SPH-FEM or even pure SPH

ben · November 2019

Dear Asalih3h,

Modelling turbulence near the wall is a complex topic and there had been limited work on this in SPH, primarily because of 2 reasons: (i) turbulence modelling itself in SPH is still in its infancy, (ii) the treatment of boundaries in SPH is a grand challenge (see https://spheric-sph.org/grand-challenges), especially ensuring that the correct shear stress is imposed.

There have been a few limited studies in SPH on wall-bounded turbulence (Robinson and Monaghan 2011 doi: 10.1002/fld.2677, Ferrand et al. 2013 doi: 10.1002/fld.3666, Mayrhofer et al. 2013 doi: 10.1016/j.cpc.2013.07.004, Mayhofer et al. 2015 doi: 10.1016/j.compfluid.2015.03.029), but at this time there is no rigorous treatment of the wall shear stress for turbulent flows in SPH. However, there are now several research groups in the world beginning to examine this, so keep your eye open for new research in the next few years

Ben

Asalih3d · November 2019

@JOJO yes, this was also what I felt, that SPH is still struggling a bit in this area.

@ben thanks for clarifying! Good to hear work is being put into this - one of my main problems with SPH is the artificial dissipation, so hoping that some more turbulent schemes for SPH pops up in the future.

Kind regards

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How does SPH resolve the wall with regards to turbulence?

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