OpenMDAO External Code Component with mpi

Question

I am trying to optimize an airfoil using openMDAO and SU2. I have multiple Designpoints that i want to run in parallel. I managed to do that with a "Parallel Group" and XFoil. But i now want to use SU2 instead of XFoil.

The Big Problem is, SU2 by itself, is started by MPI (mpirun-np 4 SU2_CFD config.cfg). Now i want openMDAO to divide all the available processes evenly to all DesignPoints. And then run one SU2 instance per Designpoint. Every SU2 instance should then use all the processes that openMDAO allocated to that DesginPoint.

How could i do that?

Probably wrong approach: I played around with the external-code component. But if this component gets 2 processes, it is run twice. I dont want to run SU2 twice. I want to run it once, but using both available processes.

Best Regards David

Answer 1

I don't think your approach to wrapping SU2 is going to work, if you want to run it in parallel as part of a larger model. ExternalCodeComp is designed for file-wrapping and spawns sub-processes, which doesn't give you any way to share MPI communicators with the parent process (that I know of anyway).

Im not an expert in SU2, so I can't speak to their python interface. But Im quite confident that ExternalCodeComp isn't going to give you what you want here. I suggest you talk to the SU2 developers to discuss their in-memory interface.

Answer 2

I couldn't figure out a simple way. But I discorvered ADflow: https://github.com/mdolab/adflow.

It is a CFD-Solver that comes shipped with an OpenMDAO-Wrapper. So I am going to use that.