[Tonio23]

Dear all,

Does SU2 implement any non-reflecting boundary condition?

I'm currently trying to simulate the flow around a wall-mounted wing. The wind tunnel extends six chord lengths downstream of the airfoil. The idea is to replicate the experiment of Chow et al. [1] using SU2 RANS simulations. The domain geometry can be seen in the NASA turbulence model resource webpage [2].

One problem I encountered was the outflow boundary condition imposition. As observed by other authors [3], if a constant pressure boundary condition is imposed at the outflow, problems arise. This because, as said by Churchfield et al. in [3]: "a vortex has low pressure within its core, and the wingtip vortex being generated in this flow is convected downstream and out of the domain, problems arise when using a constant pressure outflow boundary. With the turbulence models that predict a less diffuse vortex, the vortex encounters a large adverse pressure gradient as it approaches the boundary, causing it to periodically burst, which does not allow for a steady-state solution."

Since I only have found a constant pressure outflow condition on the SU2 documentation, I would like to ask if there is any other boundary condition already implemented which can deal with this type of flow.

[1] https://arc.aiaa.org/doi/10.2514/2.1
[2] https://turbmodels.larc.nasa.gov/Oth...p0012_exp.html
[3] https://arc.aiaa.org/doi/abs/10.2514...rnalCode=aiaaj

[bigfootedrockmidget]

Yes, for compressible flows the Riemann boundary conditions are implemented and also Giles' boundary condition.
A tutorial for Riemann is here:
https://su2code.github.io/tutorials/NICFD_nozzle/


Unfortunately these implementations are not well covered in the documentation.

[Tonio23]

Originally Posted by bigfootedrockmidget

Yes, for compressible flows the Riemann boundary conditions are implemented and also Giles' boundary condition.
A tutorial for Riemann is here:
https://su2code.github.io/tutorials/NICFD_nozzle/


Unfortunately these implementations are not well covered in the documentation.

Thank you very much for the answer.



If one is interested I've found the two papers where they implement these boundary conditions.


Riemann BC -> [1] page: 5-6
Giles BC -> [2] chapter: 3



[1] https://arc.aiaa.org/doi/10.2514/6.2015-2760

[2] https://repository.tudelft.nl/islandora/object/uuid:10797924-e37c-4328-a53a-55c5fdc464c3/datastream/OBJ/download

[jyotir]

Originally Posted by bigfootedrockmidget

Yes, for compressible flows the Riemann boundary conditions are implemented and also Giles' boundary condition.
A tutorial for Riemann is here:
https://su2code.github.io/tutorials/NICFD_nozzle/


Unfortunately these implementations are not well covered in the documentation.

Have a query about the Giles BC. What I have found from various posts is, in SU2, Giles BC can be applied only for a TURBOMACHINERY problem. Any pointer to where/how it is/can be applied to a general (non-TURBOMACHINERY) problem will be of great help.

Thank you and regards,
Jyoti