Axisymmetric flow problem in constricted pipe

RodriguezFatz · November 6, 2015, 06:43

I know what DNS means. Your discretization scheme has a certain numerical diffusion. If this is not low enough you can't do any DNS or LES, basically your DNS becomes some kind of LES.

kozden · November 6, 2015, 06:52

My time integration scheme used in DNS works is IMEXOrder2 (ImplicitExplicitOrder2) and as far as I know it has a numerical diffusion low enough to solve the problem with DNS method. I've compared my DNS work with other DNS studies in the literature and our results are matched exactly.

Regards,
Kamil

RodriguezFatz · November 6, 2015, 06:54

And the spatial disrectization?

kozden · November 6, 2015, 07:08

Continuous Galerkin projection is used in Nektar++ for spatial discretisation of NS Equations.

Regards,
Kamil

RodriguezFatz · November 6, 2015, 07:36

Ok, and how fine was the mesh in the separation region?

kozden · November 6, 2015, 07:48

There are almost 2 million grid points at a region 5D after constriction.

Regards,
Kamil

Mikhail · August 16, 2023, 10:28

Hi!
I try to simulate similar process - can you share geometry (blockMesh) ?

November 6, 2015, 06:43		#21
RodriguezFatz Senior Member Philipp Join Date: Jun 2011 Location: Germany Posts: 1,297 Rep Power: 27	I know what DNS means. Your discretization scheme has a certain numerical diffusion. If this is not low enough you can't do any DNS or LES, basically your DNS becomes some kind of LES. __________________ The skeleton ran out of shampoo in the shower.

November 6, 2015, 06:54		#23
RodriguezFatz Senior Member Philipp Join Date: Jun 2011 Location: Germany Posts: 1,297 Rep Power: 27	And the spatial disrectization? __________________ The skeleton ran out of shampoo in the shower.

November 6, 2015, 07:36		#25
RodriguezFatz Senior Member Philipp Join Date: Jun 2011 Location: Germany Posts: 1,297 Rep Power: 27	Ok, and how fine was the mesh in the separation region? __________________ The skeleton ran out of shampoo in the shower.

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November 6, 2015, 06:52		#22
kozden New Member Kamil ÖZDEN Join Date: Feb 2013 Posts: 27 Rep Power: 13	My time integration scheme used in DNS works is IMEXOrder2 (ImplicitExplicitOrder2) and as far as I know it has a numerical diffusion low enough to solve the problem with DNS method. I've compared my DNS work with other DNS studies in the literature and our results are matched exactly. Regards, Kamil

November 6, 2015, 07:08		#24
kozden New Member Kamil ÖZDEN Join Date: Feb 2013 Posts: 27 Rep Power: 13	Continuous Galerkin projection is used in Nektar++ for spatial discretisation of NS Equations. Regards, Kamil

November 6, 2015, 07:48		#26
kozden New Member Kamil ÖZDEN Join Date: Feb 2013 Posts: 27 Rep Power: 13	There are almost 2 million grid points at a region 5D after constriction. Regards, Kamil

August 16, 2023, 10:28		#27
Mikhail New Member Mike Join Date: Aug 2023 Posts: 2 Rep Power: 0	Hi! I try to simulate similar process - can you share geometry (blockMesh) ?