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Old 08-19-2017, 06:59 PM   #21 (permalink)
The Toecutter
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Join Date: May 2010
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Rebellion - '16 KMX Framekit Custom electric velomobile
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Quote:
Originally Posted by aerohead View Post
Your trike is gonna be more like a 2-dimensional airfoil than a 3-D bluff body.
Noted. I've seen bluff bodies with a Cd in the low 0.3 range and figured that I could get similar results, and then tweak it over time after the turbulent areas were found.

Quote:
A symmetrical airfoil section with an aspect chord-to-thickness ratio of 3.92:1 has been found to be the center of the drag 'bucket',with both minimum pressure and skin friction drag.
You could maybe think in terms of both the body and canopy designed around this geometry instead of the template.
Would this be very close to the NACA 0025 and 0026 airfoils?

Quote:
I agree with the others on the front lower angle.I wouldn't do that.
All the intersections will have hook-vortices unless there's a fillet to smooth the intersections.
Noted. I worry about speedbumps and potholes. I will have a ground clearance of roughly 5.5 inches when all is said and done.

Quote:
Goro Tamai's book on solar racers would have some data you could use in addition to member comments,of which have,'been there,done that!'.
Thanks. I have not even heard of this book and feel compelled to read it. I do plan to put solar panels on this thing some day, and a body with a lot of flat-surfaced top area with minimal sources of shade would be good for this. Fitting a 0.5 m^2 set of panels at some point in the future is a nice thought.

Quote:
Rumpler's Tropfenwagen was Cd 0.28 for the closed limousine,and Cd 0.54 for the roofless,open touring car.
I didn't know what it was for the open top car. I knew that the enclosed model was a 0.28, roughly what the average 2017 model year car claims to have(and usually, independent wind tunnels put their figures a bit higher, Tesla being about the only exception that has consistency between manufacturer claims and independent verification).

Quote:
Without a half-bubble windscreen Cd 0.25 may be problematic.
Noted. I plan to make a removable ducted cover section with a roof and windscreen to shield the rider's head, but I'd like the aerodynamics to be good enough to where it isn't really needed.

Quote:
One of the IHPV members ran a all-Coroplast-bodied trike in 2014 at Battle Mountain,and I want to say that he came through the 5-mile trap at 47-mph.
I'm pretty sure that the wheels were enclosed and he had a bubble screen.
I've seen pictures of it:



Unfortunately, my trike is too wide to make that sort of body work for my needs. It is well done.


Last edited by The Toecutter; 08-19-2017 at 07:06 PM..
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