Feedback on AKABAK SEOS analysis

Hi all,

Hope I'm posting this in the right place, apologies if not.

I'm looking on some feedback for an analysis I've completed in AKABAK. I followed Austin Mys tutorial on setting up a waveguide in AKABAK as well as using the flange baffle trick as the geometry around the mouth is a bit complex and I encountered the No Data-set in polar error. I've also looked at some tutorials on the AKABAK website.

Is there anything that you might see as a standout error? Is there any way of checking this is correct using hand calculations or other sort of sense checks? Not sure how to make sure its correct myself. Is there anything I could do to make it more accurate? I'm thinking maybe making the mesh more dense and increasing the resolution at which frequencies are measured.

On my radiation plot, I'm not really sure why at 0deg I don't get a frequency response curve, but I do at all other degrees?


Please see images below. Cheers!

Screenshot 2024-01-04 223754.png
Screenshot 2024-01-04 223707.png


Screenshot 2024-01-04 223853.png

Screenshot 2024-01-04 224050.png
 
I doubt that is accurate. There is a very small number of elements, there is a large deviation in the external subdomain which suggests a mesh problem.

You do have a response at 0 degrees it is the flat red line starting at 500Hz, because you normalized the plot to 0 degrees :)
 
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Thank you, I'll give it a go with a tighter mesh. How can you tell there is a deviation in the external subdomain? Is it from the values given in the calculation log or just visually seeing they don't line up?

I see, that makes sense regarding the response. If I wanted to see the response right down 0 deg, I'm assuming I switch normalisation off.
 
The Std deviation in the external subdomain is quite high and usually indicates a mesh problem.

It's often better to simulate without normalization, as the graph can be duplicated and normalized in VACS, but not so easy to undo it when baked into the data.

If you want to send me or attach the CAD step file you used I can have a look. The throat looks very long for a SEOS waveguide, I thought they were all quite short.