Hmm, interesting thought.
In vaguely related field, jet engine test cells use a oval cross section exhaust duct/muffler as well. A jet engine test cell is basically a building where they bolt a jet engine down for operational testing. The exhaust from the engine is directed out the back of the building through a long ~10 FT diameter pipe and then against a baffle which directs it upward. The pipe is constructed basically like a big glass pack muffler; with a solid outer shell, a bunch of lead and steel wool, and perforated inner panels. There are also baffled air inlets to the building to provide air to the engine while it's running. The whole idea is to absorb sound so you're not shaking the windows out of nearby buildings while you're testing the engine at WOT. Here's a picture of one i worked on at NAS New Orleans some years ago:
Up until recently, the ducts were oval in cross section. Then somebody did some experiments with a scaled one made with a square cross section, which would be much simpler to fabricate. Turns out the square one did an even better job than the oval one of killing the sound. I'm not sure if they've built one yet; a couple of guys I used to work with were trying to push a project through to build one like this but their boss was EXTREMELY conservative and nixed the idea.
Anyway, it occurs to me, maybe a square cross section muffler would work better at absorbing sound.
OK- who's gonna try the first square cross section muffler?
Originally Posted by Hughlysses
Hmm, interesting thought.
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