CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   OpenFOAM Running, Solving & CFD (https://www.cfd-online.com/Forums/openfoam-solving/)
-   -   Euler, Backward time schemes (https://www.cfd-online.com/Forums/openfoam-solving/81453-euler-backward-time-schemes.html)

 idrama October 27, 2010 08:04

Euler, Backward time schemes

Dear Foamers,

hopefully someone has already experience with the Versteeg book and the Euler and backward time scheme. In Versteeg, three schemes are discussed from which I don't know which belongs to Euler and which to backward. Can anybody help?

 santiagomarquezd October 27, 2010 14:06

If I interpreted well, Versteeg discusses three temporal schemes: explicit, fully implicit and Crank Nicholson, where fully implicit stands for Backward Euler and explicit for Forward Euler. Explicit scheme ins't implemented in FOAM as an option for Time Schemes, Crank Nicholson is the same (but you can tune up a parameter), Backward Euler is Euler in FOAM. Finally Backward from FOAM is not explained in Versteeg I think, and basically is a second order time scheme, using previous, actual and next time step data.

Regards.

 idrama October 27, 2010 17:48

Let me change my question: is backward just the backward differencing formula approach (BDF) ?

 santiagomarquezd October 27, 2010 18:09

Backward Scheme formulation is explained in Programmer's guide as a second order scheme in stead of backward differencing, that, at least as I know it, is a first order differencing scheme.

Regards.

 SINA.KHAYYAM December 17, 2015 10:16

Quote:
 Originally Posted by santiagomarquezd (Post 281093) Backward Scheme formulation is explained in Programmer's guide as a second order scheme in stead of backward differencing, that, at least as I know it, is a first order differencing scheme. Regards.
Dear Santiago MÁRQUEZ DAMIÁN,
I want to implement the Forward Euler scheme in open Foam. In order to write it i need to get help from its Backward scheme. Unfortunately i cannot find it in Open Foam. I would like to know if you can show me the suitable path in Open Foam to get it and compare it with the Forward scheme which i wrote.