CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   OpenFOAM (https://www.cfd-online.com/Forums/openfoam/)
-   -   Setting up LES of Airfoil in OpenFoam (https://www.cfd-online.com/Forums/openfoam/152914-setting-up-les-airfoil-openfoam.html)

Jack001 May 12, 2015 10:28

Setting up LES of Airfoil in OpenFoam
 
Hi all, first post so sorry if I have already screwed up by posting here...

I wish to get into some high fidelity simulation of the sound created by the flow over a simple NACA airfoil using LES to model the sound sources in OpenFoam. I have managed to set up the case of solving RANS equations in OpenFoam using the simpleFoam solver. Up until now this has been relatively straightforward due to tutorials available online, but there is almost nothing on unsteady CFD modelling of an airfoil in OpenFoam, hence I am completely lost. Is there anyone out there that can walk me through how to set up a test case of using LES (or even DNS) of an airfoil? My Reynolds number of interest is relatively small (lets say 30,000 based on chord and I am mainly interested modelling the development of transition behaviour on the suction side and interaction with the trailing edge.

I intend to use the GMSH utility to create my Mesh about the airfoil.

Any advice would be greatly appreciated!

taxalian May 12, 2015 18:32

Are you interested in performing Hybrid RANS-LES type approach i.e. Detached Eddy Simulation.

In general, for LES you need a very high resolution hexahedral mesh and in order to capture the transition behavior over the suction side of the airfoil. In OpenFOAM there exists a transition model i.e. kklOmega turbulence model.

Make sure that this turbulence model works with the LES model, then you can perform the LES+transition modelling of an airfoil in OpenFOAM.

In OpenFOAM, there exists unsteady solvers like pimpleFoam in "tutorials/incompressible" folder, there you will find several tutorials.

Jack001 May 13, 2015 14:50

Thank you for your reply! I am interested in pure LES although I'm not sure - maybe the hybrid approach is possible as well.

So how would I start to experiment with this kklOmega turbulence model using pimpleFoam? I generally have no idea how to go about changing the turbulence model for a particular case, but I guess I could experiment. Particularly I'm not sure what I need to modify on the constant/ system directories of the problem I'm solving.

Another issue is that lets say I get everything to run. What is the best and quickest way to verify that my simulation is converging to a feasible solution? Should I look at mean quantities like pressure coefficient profile over the airfoil and compare to those of a RANS study I have done of the airfoil?

zeinelserfy October 3, 2019 00:57

have you succeeded in simulation it
 
Have you succeeded in running pure les simulation for flow around aerofoil as I am interested in that case?


All times are GMT -4. The time now is 15:36.