[gdsilva]

Hello, everyone.


I am new using OpenFOAM, and I am having difficult on how to set a different model to an existing tutorial.


My main objective is to use the airFoild2D tutorial case as my baseline and compare different models to the same mesh and geometry.


To get started, I want to use the tutorial $FOAM_TUTORIALS/incompressible/simpleFoam/airFoil2D but change the model to k omega SST.


I know I have to do the following steps until now:

• have the k and omega file at the 0 folder;
• change the turbulence model to kOmegaSST
• add to fvSolution k and omega parameters.

Is there any more tips or something that I should do to have a minimal setup simulation? k and omega files have something special to do?

I do not want cooked answers, but some tips or an overview on how would you set up this case, so I can learn the procedure on how to make this simulation.

[Yann]

Hello,

Your steps sound good.

Basically: each turbulence model solves different equations and requires to define different variables (boundary conditions for these variables, and numerical setup in fvSolution/fvSchemes)

If you want to be able to switch between turbulence models, you just need to prepare your 0 directory and fvSolution/fvSchemes to include the variables your need for each model you want to use (some models will rely on the same variables, such as k and epsilon for all the k-epsilon models variants, etc...)

It looks like this is already what you are doing. What are you struggling with?

You can have a look to $FOAM_TUTORIALS/incompressible/simpleFoam/pitzDaily which does exactly this: it is setup to be able to switch between turbulence models. You just have to switch models in turbulenceProperties.

Regards,
Yann

[gdsilva]

Thank you, Yann

Originally Posted by Yann

It looks like this is already what you are doing. What are you struggling with?

My struggle was to guarantee that the simulation was correct, since I just copied the airFoil2D tutorial that I said, changed the model and ran the simulation. For each given error, I added the necessary file (copied from other tutorials and adapted to the airfoil mesh) on and on until get no more errors. As I am new to OpenFOAM, I was not confident if that is the way to go.

Originally Posted by Yann

You can have a look to $FOAM_TUTORIALS/incompressible/simpleFoam/pitzDaily which does exactly this: it is set up to be able to switch between turbulence models. You just have to switch models in turbulenceProperties.

The pitzDaily really does what I am intended to do, I did not know it. Looking at the files, I noticed that I could just put all the mandatory constants for all models in the 0/ folder, set them up and for each simulation just change the model turbulenceProperties.

Thanks again!

Regards,
Gabriel

[Yann]

Hello Gabriel,

Originally Posted by gdsilva

For each given error, I added the necessary file (copied from other tutorials and adapted to the airfoil mesh) on and on until get no more errors. As I am new to OpenFOAM, I was not confident if that is the way to go.

This the usual way indeed!

Originally Posted by gdsilva

Looking at the files, I noticed that I could just put all the mandatory constants for all models in the 0/ folder, set them up and for each simulation just change the model turbulenceProperties.

Absolutely, you can setup the case to run with every turbulence model you want, and then you will just need to switch between models in turbulenceProperties.
Just be careful to update the boundary conditions for all the turbulent quantities if you change a parameter which could affect these quantities (like changing the flow velocity)

Cheers,
Yann