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Fourth Order Runge Kutta time integration

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Old   May 22, 2019, 04:16
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Syavash Asgari
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Quote:
Originally Posted by Hen Cruise View Post
Hi, syavash, thanks very much for your great work, and i want to know,

Is it possible to modified the 'RK4' be an convenient 'option' in fvschemes file for ddtSchemes such as 'Euler' or 'backward'? then used for most compressible or incompressible solvers?
Well, I think it would be a great idea! However, it cannot be employed as a temporal scheme in the current form. Probably some if-clause will be necessary to differentiate between incompressible and compressible conditions.

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syavash
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Old   July 1, 2019, 19:10
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Hey Syavash,

It is clear from the code that solver running time highly depends on the number of times the pressure correction step is implemented. Do you think that there is a way to reduce the number of the pressure correction step while maintaining the 4th-order RK projection for the velocity field? For example, if one only evokes the pressure correction at the end only once or twice between intermediate time steps.

Thanks
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Old   July 2, 2019, 09:19
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Syavash Asgari
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Quote:
Originally Posted by kermelosh View Post
Hey Syavash,

It is clear from the code that solver running time highly depends on the number of times the pressure correction step is implemented. Do you think that there is a way to reduce the number of the pressure correction step while maintaining the 4th-order RK projection for the velocity field? For example, if one only evokes the pressure correction at the end only once or twice between intermediate time steps.

Thanks
Hi,

I can only think of the 3rd-order Runge-Kutta as a reply, which is of-course 3rd-order accurate in time but demands fewer number of pressure correction steps. I have already implemented that and it was faster, but don't remember it gave a huge difference over 4th-order Runge-Kutta.

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Syavash
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Old   July 2, 2019, 09:37
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Syavash Asgari
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Well, I have uploaded both solver and its test case on my Github repository. On my reposityory, one can also find a bunch of useful codes WRT incompressible LES in OpenFoam.

https://github.com/syavash20/TurbLab

Best Regards,
Syavash
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Old   December 20, 2019, 19:13
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Hey Syavash,

In your opinion, can the RK4Foam solver be used for an FSI study? I would like to explore its application for FSI studies with LES turbulent modeling.
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Old   November 10, 2022, 02:36
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Nico
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Hi Ville,
i tried to implement a fully explicit RK4 scheme for compressible flows (Euler Equations) , following your paper, but it seems that not work ( some waves are created near the boundaries )

Can you give me some explanation about that, thank you.
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