Quote:
Originally Posted by JulianEdgar
This is one occasion when copying one of the generic low-drag shapes will probably get you 90 per cent there.
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I did that already, and it's definitely not 90% there, maybe 30% there, although I think that has a lot to do with the fact that I still have outboard open wheels. Due to the clearance issues posed with the steering geometry and suspension, wheel wells were difficult to implement. I wanted to avoid having large wheel well gaps and needed to retain access to the brake calipers and axle for maintenance/repairs(often on a sidewalk 30+ miles from home), so the first two shells had open/outboard wheels. And that is really bad for drag.
I made some farings for the front wheels out of aluminum, but they actually added drag. I didn't have them shaped right and their frontal area penalty likely outweighed any drag coefficient reduction they provided for the wheels, plus the backs of the farings seemed to act as parachutes. I over-sized the clearances for them because I did not want them to give me a flat tire, and even then there was a bit of rub that had to be corrected!
I'm working on a set of more narrow profile farings that may actually show an aerodynamic benefit. We'll see.
I think I solved how to shape the wheel wells for an inboard wheel design with an inverted half-toroid shape, which should hopefully allow operation without any tire scrubbing during cornering or over rough roads, for the next design iteration. If successful, I expect greatly reduced overall drag.