Amateur aerodynamics
- Thread starter Jim Gerwing
- Start date
Jim Gerwing
Well-Known Member
Cheap aero
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Andrew Baloga coined the term in a recent post.
My design philosophy is 'anything worth doing is worth doing badly (at least in the beginning)'.
My design philosophy is 'anything worth doing is worth doing badly (at least in the beginning)'.
Jim Gerwing
Well-Known Member
Proof of concept
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Made of 4ply card stock and acrylic packaging (and lots of packing tape-I'm on my third roll this summer).
Jim Gerwing
Well-Known Member
Plywood frame
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Jim Gerwing
Well-Known Member
Mounted
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Jim Gerwing
Well-Known Member
A view from the cockpit
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Jim Gerwing
Well-Known Member
Find Waldo
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Jim Gerwing
Well-Known Member
?
I don't know why that last picture is so distorted.
Due to safety concerns I can't take this on my regular route.
I did take it on my early season route which is a 10k beauty.
I averaged a little over 45km/hr with a slight wind at my back. My return leg was 14:28 which is 8 seconds off my best time on this road. Not a bad result considering it was against a slight wind.
The front fairing adds a noticeable mass but doesn't seem to slow me down. I have a lot less time to spend on the project this season but I do have one more idea to roll in.
I'm inclined to seek out an engineering student who wants an aerodynamics project this winter. It sure has been fun this season (and its not over yet).
JG
I don't know why that last picture is so distorted.
Due to safety concerns I can't take this on my regular route.
I did take it on my early season route which is a 10k beauty.
I averaged a little over 45km/hr with a slight wind at my back. My return leg was 14:28 which is 8 seconds off my best time on this road. Not a bad result considering it was against a slight wind.
The front fairing adds a noticeable mass but doesn't seem to slow me down. I have a lot less time to spend on the project this season but I do have one more idea to roll in.
I'm inclined to seek out an engineering student who wants an aerodynamics project this winter. It sure has been fun this season (and its not over yet).
JG
Charles.Plager
Recumbent Quant
do it. do it. Do it. Do it.
do it. do it. Do it. Do it. Do It. Do It. DO IT. DO IT. DO IT! DO IT!!!!
(it = fairing and sock. I'd love to see it!!!)
do it. do it. Do it. Do it. Do It. Do It. DO IT. DO IT. DO IT! DO IT!!!!
(it = fairing and sock. I'd love to see it!!!)
Jim Gerwing
Well-Known Member
No, no, No, Eric
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Jim Gerwing
Well-Known Member
Or
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marshall2389
Guru
I would be very impressed to
I would be very impressed to see the sock work with the V's MBB (i.e. moving front end)
I would be very impressed to see the sock work with the V's MBB (i.e. moving front end)
hamishbarker
Well-Known Member
the cruzbike forum has
the cruzbike forum has officially jumped the shark.
the cruzbike forum has officially jumped the shark.
Charles.Plager
Recumbent Quant
I would be very impressed to
Well, it is just stretchy fabric (and at speed, there isn't too much movement anymore).
The Vendetta probably isn't the right bike for that as the rider is probably too horizontal. The Silvio V1.X, however, is probably perfect!
Well, it is just stretchy fabric (and at speed, there isn't too much movement anymore).
The Vendetta probably isn't the right bike for that as the rider is probably too horizontal. The Silvio V1.X, however, is probably perfect!
Jim Gerwing
Well-Known Member
Rip-stop fairing extension
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Jim Gerwing
Well-Known Member
Commentary
Eric anticipated my next addition.
I've had it out a couple of times: earlier today was windy enough to call off a fair try, tonight the wind was negligible but the results were marginal. I am limited by the lack of free time (probably for the rest of this season) and a decent and safe(enough) road. My combined time tonight resulted in an average speed of 44km/hr over 20km which is near my PB but I have higher expectations. The sides really compress at speed. I suspect that I'm paying aerodynamic costs for whatever aerodynamic benefits I'm getting from the fairing plus skirt. The 'hem-line' could go lower but I want a quick escape if necessary. I have ideas for supporting the rip-stop but they are time consuming. Maybe the composite version is the next best place to concentrate my efforts?
JG
Eric anticipated my next addition.
I've had it out a couple of times: earlier today was windy enough to call off a fair try, tonight the wind was negligible but the results were marginal. I am limited by the lack of free time (probably for the rest of this season) and a decent and safe(enough) road. My combined time tonight resulted in an average speed of 44km/hr over 20km which is near my PB but I have higher expectations. The sides really compress at speed. I suspect that I'm paying aerodynamic costs for whatever aerodynamic benefits I'm getting from the fairing plus skirt. The 'hem-line' could go lower but I want a quick escape if necessary. I have ideas for supporting the rip-stop but they are time consuming. Maybe the composite version is the next best place to concentrate my efforts?
JG
Jim Gerwing
Well-Known Member
And. . .
A set of aero handle bars that will put my hands and most of my arms 'inside the pocket'.
JG
A set of aero handle bars that will put my hands and most of my arms 'inside the pocket'.
JG
Eric Winn
Zen MBB Master
I think the sock needs to be
I think the sock needs to be continuous from front to back to do you any good.
And similar to Charles observation, the recline of the Vendetta and the need for feet and knee clearance may require a shape more akin to the Milan velomobile which has feet and knee "bumps".
See: http://www.velomobilix.de/Velomobile/Milan/milan.html
-Eric
I think the sock needs to be continuous from front to back to do you any good.
And as you state, your hands and handlebars need to be inside the sock.
And similar to Charles observation, the recline of the Vendetta and the need for feet and knee clearance may require a shape more akin to the Milan velomobile which has feet and knee "bumps".
See: http://www.velomobilix.de/Velomobile/Milan/milan.html
-Eric
