CFD Online Discussion Forums

Dual-Booting : win7 & linux-mint

Posted August 28, 2016 at 19:50 by kindle
Updated June 7, 2017 at 13:20 by kindle (clarity)

Installation from nothing : First win7 then linux-mint.
Win7 writes in MBR something to control boot and linux uses grub to control boot which will be able to boot windows.
Why not in the reverse order?
A complete re-installtion of win7 may over write ALL in MBR meaning the part that will call the actual grub configuration (in /boot or /etc/grub.d not sure...), therefore the repair of the linux booting is needed.
Result: grub boot first, if you choose "windows"...

kindle

New Member

Posted in system

Views 1741 Comments 0 kindle is offline

Numerics in OpenFoam - PBiCG vs. PCG

Posted August 18, 2016 at 15:13 by kindle
Updated February 23, 2017 at 04:13 by kindle

So the numerical scheme (fvScheme) will affect the property of the matrix to invert and we should choose properly the solver/solving algorithm (fvSolution) in order to solve it properly. Depending on the form of matrix depended on structured or unstructured mesh something like that.

Quote:

Originally Posted by thg

Hi Frog,

Meindert already mentioned, the difference between a PCG or a PBiCG,...
you can find in any textbook about linear iterative solvers like
Wessling, Saad, Trefethen, Stran,....

...

kindle

New Member

Posted in Solver

Views 1629 Comments 0 kindle is offline

Compile the solver laplacianFoam

Posted August 17, 2016 at 11:22 by kindle
Updated February 23, 2017 at 04:13 by kindle

laplcacianFoam is an implemented solver in OpenFOAM, which can be found in WM_PROJECT_DIR/platforms/.../bin (executable), .../application/solver/basic (dep) and WM_PROJECT_DIR/application/solver/basic (src).

Tried to compile from $FOAM_RUN, using laplacianFoam1. After comparing with authentic one, success.

kindle

New Member

Posted in programming, Solver

Views 1441 Comments 0 kindle is offline

Writing the last iteration for steady state simulations

Posted August 17, 2016 at 06:09 by Ramwi

Tags controldict, functionobjects, steady-state

Ok, I have a very bad memory and furthermore, I did not find the solution to the bellow described problem right away. So, I will use this place to store the solution for future use.

Note: The proposed approach might be overcomplicated. If it is so, please let me know what is the "proper way".

Problem description: You run a steady state simulation (e.g. simpleFOAM) and you control the endTime (number of iterations) via the residualControl. Thus, the number of iterations...

Ramwi

New Member

Posted in Tips and tricks

Views 1989 Comments 1 Ramwi is offline

Accessing internal field and mesh from within boundary condition

Posted August 6, 2016 at 08:00 by kaifu

very useful.

Quote:

Originally Posted by mchurchf

Thank you all for your help,

I was able to implement my boundary condition as well. I used the following code to access the internal velocity field and the mesh two layers of cells inward from the boundary:

Code:

//  Set up access to the internal velocity field and mesh
    const volVectorField& U =
        db().objectRegistry::lookupObject<volVectorField>(UName_);
    const fvMesh& mesh = patch().boundaryMesh().mesh();

...

kaifu

Member

Posted in Uncategorized

Views 1147 Comments 0 kaifu is offline