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Frank · 01-01-2020, 08:27 PM

Hi freebeard,

It does taper to a pretty sharp point, about 16" change in width over the 30" length which I think is about 14* per side. I chose a sharp closure thinking I might try some VG's to keep flow attached. One reason I chose not to implement full leg cut-outs was that the initial width could be less. The width at the back of the front fairing is wider (22"?) so it's in the shadow of that. Part of the plan for next season is to tuft it and figure out how to take some pics and if necessary try some VG's to see if they do anything.

I'm limited by rules in that the back of the tail cannot be more than 10" from the back of the rear tire, and the height from pavement has to be between 4" and 40". Much lower than that and you can have trailer loading problems and interference issues when cornering (don't ask, lol).

The surface finish is pretty rough: is it worthwhile to try to smooth it out? It's been laid up with biaxial 1708 and polyester resin. I suspect the rough finish might keep the boundary layer area energized but don't really know. Reynolds number is pretty high. So much to try to understand.

Thanks for your comments.

01-01-2020, 08:27 PM	#5 (permalink)
Frank EcoModding Lurker Join Date: Jan 2008 Location: Maine/Nova Scotia Posts: 88 Thanks: 9 Thanked 22 Times in 14 Posts	Hi freebeard, It does taper to a pretty sharp point, about 16" change in width over the 30" length which I think is about 14* per side. I chose a sharp closure thinking I might try some VG's to keep flow attached. One reason I chose not to implement full leg cut-outs was that the initial width could be less. The width at the back of the front fairing is wider (22"?) so it's in the shadow of that. Part of the plan for next season is to tuft it and figure out how to take some pics and if necessary try some VG's to see if they do anything. I'm limited by rules in that the back of the tail cannot be more than 10" from the back of the rear tire, and the height from pavement has to be between 4" and 40". Much lower than that and you can have trailer loading problems and interference issues when cornering (don't ask, lol). The surface finish is pretty rough: is it worthwhile to try to smooth it out? It's been laid up with biaxial 1708 and polyester resin. I suspect the rough finish might keep the boundary layer area energized but don't really know. Reynolds number is pretty high. So much to try to understand. Thanks for your comments.