I'm not an engineer, but I've been tasked with something that's a bit out of my depth. I'm hoping to find some help here. I'm a graphic designer for a manufacturer of wood ceilings, and I'm working on some informational literature concerning the acoustical properties of our products. I have a chart showing the noise reduction coefficient as related to the % open area of a wood panel - the problem is figuring out where our products fall on that chart.
The easy part was our perforated panels - they either have round holes or rounded-end slots that go straight through. I was able to calculate those using these websites: https://www.hendrickcorp.com/perforated/resources/open-area-calculator/; http://www.rmig.com/en/technical+info/formulae/calculation+open+area.
Now I'm attempting to do the same for our panels that have a channelled front and perforated back. This is much more complex, and I have no idea what to do. Please see the attached drawing - i basically need to figure out how much material is removed from the panel by the channels and perforations. The "edge detail" parts should not factor in - that is showing one of a few different mounting styles that we do, and is not related to the noise reduction coefficient.
I'm lost... please help!