PyFR for jet noise

Hello,

I’m interested in studying the flow and noise from two-stream internally-mixed supersonic nozzles, and I’m wondering how suitable PyFR would be for this application. I’ve read through the documentation, forum, and searched for relevant papers but I still have a few questions.

  • An issue I’ve seen with a similar solver is the need for quite a bit of parameter tuning to handle shocks. I saw that in June, Will mentioned that “With the new entropy filtering that is available on the current develop branch, PyFR works quite well for transonic and supersonic cases without much parameter tuning.” Would you still say this works pretty well out of the box? Has it been tested much?
  • I would like to output periodic planar slices from the simulation for visualization, as well as the surface of a conical frustum for jet noise calculations (a Ffowcs Williams Hawkings/FWH surface). It appears I can use the rectangular cuboid region to output planar slices, but it’s not clear that I could output only the surface of a conical frustum. Is there any way to do this? Would creating a conical frustum region and then subtracting an infinitesimally smaller conical frustum work?
  • Do you know of anyone who has run similar simulations? I’ve seen some references to a group that simulated chevron nozzles using PyFR but I haven’t found much info on how that went.

Thanks!

Entropy filtering works very well. Saying that, a bad mesh is still a bad mesh and no amount of filtering or numerical trickery will change that. Thus, if you construct a good mesh you will likely have good results with entropy filtering.

PyFR now has an FWH plugin which may make your life a bit simpler. However, if you do want to output just a single layer of elements then yes, you can construct a region which consists of one conical frustum subtracted from another.

Regards, Freddie.

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