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-   -   Choise of ddtSchemes regarding Dynamic Mesh Refinement TaylorTayleighInstability (http://www.cfd-online.com/Forums/openfoam-solving/57834-choise-ddtschemes-regarding-dynamic-mesh-refinement-taylortayleighinstability.html)

sega March 9, 2009 11:34

Hello World. I was currentl
 
Hello World.

I was currently investigating the Taylor-Rayleigh-Instability with interDyMFoam.

I'm experiencing different solutions with different ddtSchemes.

Using the Euler scheme I'm getting a far better solution which is closer to all the other solutions to this problem than with Crank Nicholson.

Have a look at this comparison at two identical time steps using different ddtSchemes:
http://therealsega.th.funpic.de/openfoam/ekt/rt.jpg

Beside the strange "notches" at the surface the main difference is that with Crank Nicholson the heavier fluid has not developed that far into the lighter fluid that with Euler.

Does anyone have an idea why this is happening?


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