I was looking at laminar flow filters to aid in my mycology work I'm doing. Most filters use an aluminum extrusion with fins. I figured the options out there are pretty expensive for what you get and figured I could just 3d print my own straightener. Question is what shape do I use? I have seen honeycomb used and would be an easy option, but it really got me thinking about what shape would be optimal for this. We all know that when streamlining a positive body that a teardrop is close to optimal, but putting teardrops in a grid would yield a weird negative shape in the pattern. Any thoughts or ideas on this would be greatly appreciated, I plan on open sourcing the final design. Thanks
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Just doing a quick search, this NASA paper (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19810020599.pdf) indicates that no particular geometry has significant advantages for producing flow uniformity. I would stick to a well-tested geometry that is the simplest to produce with a 3D printer. Also, keep in mind the purpose of using honeycomb is to remove turbulence (vortices) from the flow via reducing the hydraulic diameter. Thus, so long as you don’t inflict a large pressure drop through the honeycomb (if you care about pressure drop), any shape with an appreciable reduction in flow hydraulic diameter will reduce the turbulent intensity. This paper seems to be useful as well: https://conservancy.umn.edu/bitstream/handle/11299/108725/pr338.pdf?sequence=1
