This is a totally experimental design inspired by the one way valve originally designed in 2D by Tesla. There's a thing out there (http://www.thingiverse.com/thing:23947) with a similar design which gets used as a muffler. Maybe it also improves flow, which would be the complete opposite effect than expected. It's completely untested. The connectors are designed for connection to a shower hose for testing with water flow.

I used a libre calc sheet with a macro to generate the curve (x = 16pow(3,sin (t)), y = 13cos(t) - 5cos(2t) - 2cos(3t) - cos(4*t)) for rotary extrusion (since the assign statement didn't work that well).