Aerodynamic aspects of an old GoOne 3 velomobile

[aerohead]

When a member of IHPVA, I'd spend days with Georgi, designer of the VARNA series of bikes Sam Whittingham used to hold the speed records with.
Georgi said that the 1/4-inch gap around the wheel openings was responsible for half of VARNA's drag ( around Cd 0.11 for the bike according to the European teams' CFD analysis ).
Honda's DREAM-2 solar racer had fully- enclosed front steering wheels with cable-operated, 'lazy-Susan' turntables, which rotated exactly like an outboard motor.
If this technology could be mimicked, it seems that it would pay big dividends.
I'm going to 'simulate' it on SPIRIT during the next wind tunnel testing just to isolate their contribution ( or not ).
It might be possible to test a 'mockup' of a fully-sealed wheelhouse bottom, during a 'straight-line-only' test, requiring zero steering ( cardboard and duct-tape ).
Depending on the results, you could gage whether or not to invest the resources to fabricate something more robust.
You'd be the second man on Earth to have them.

[beate]

Not quite.

First of all, i am a woman (and therefore more complicated...).

Moreover there is already a velomobile with fully closed wheelhouses: the CAS Milan. That's a version of the Milan velomobile especially designed for a world record (24 hours men, i think. ) which has the wheelhoses closed to its maximum. The clothing patches turned with the wheels.

[aerohead]

Originally Posted by beate

Not quite.

First of all, i am a woman (and therefore more complicated...).

Moreover there is already a velomobile with fully closed wheelhouses: the CAS Milan. That's a version of the Milan velomobile especially designed for a world record (24 hours men, i think. ) which has the wheelhoses closed to its maximum. The clothing patches turned with the wheels.

Entschuldigen Sie bitte.

Please accept my apology for the lack of consideration to our global audience.
I'm afraid that I'm not far-removed from some of the knuckle-draggers depicted in cartoons.
I like to think that you'd have been inspired by the women members of the international teams competing at Battle Mountain, Nevada, in the annual IHPVA speed events. I was.
And it sounds like you're well acquainted with low-drag.
Without access to the GoOne, from the photos, it seems that turbulence within the wheelhouse region could / would compromise boat-tailing further aft on the lower body.
Wolf Heinrich Hucho and his mentor, Dr. Hermann Schlicting emphasized the importance of protecting against any pressure spikes in an aft-body, which could precipitate premature flow separation.
Steering articulation and vertical suspension travel makes it a sophisticated challenge. Fun!

[beate]

Originally Posted by aerohead

Without access to the GoOne, from the photos, it seems that turbulence within the wheelhouse region could / would compromise boat-tailing further aft on the lower body.

Yes, indeed. And that was the reason why i more or less refused to consider work on the back tailing after the unsuccessful attempts. I know how it can be done better, even without improving the wheel houses, but starting from front to back seems more reasonable to me. And working on the details - the bike has already become about 15% faster ...

... and it will always remain a Go One 3, with all its compromises. And good sides - it is actually fun to ride. If i want something faster i could go for a faster model while still putting fun and effort into the 3 yet trying to keep the "integrity" of that design intact.

[aerohead]

The Go One 3 may become a 'classic'. And since they don't just fall from trees, I understand not wanting to do anything which would be irreversible, where it 'couldn't' be returned to its original state.
I found an old drag table for human-powered vehicles, but it didn't have anything we could relate to your trike.

[The Toecutter]

I have a Milan SL. The wheelhouses aren't fully closed, but they are so narrow that the turning radius is about as terrible as a Mercedes Benz 300 SDL I used to own.

It is very slippery. Holding 35 mph on the flat is something I could do for hours if the terrain and weather were permitting, and I can almost hit 50 mph in a sprint. Reaching 50 mph takes about 2.5 miles though.

I bought the Milan so that I could take measurements of it and scale a custom body shell based upon it to my own unique build. I want a pedalable electric microcar with the Milan's shape, with compromises made for better streetability(more ground clearance, tighter turning radius, more suspension travel, hydraulic disc brakes, more storage space, ect). I expect when finished I'll have double the Milan's drag. I like to imagine what maintaining 120 mph on only 6 horsepower would be like!

Originally Posted by beate

Not quite.

First of all, i am a woman (and therefore more complicated...).

Moreover there is already a velomobile with fully closed wheelhouses: the CAS Milan. That's a version of the Milan velomobile especially designed for a world record (24 hours men, i think. ) which has the wheelhoses closed to its maximum. The clothing patches turned with the wheels.

[freebeard]

Rigid body, rigid wheel pants, flexible fillets made of knitted dragon scale chain maille?

www.youtube.com/results?search_query=dragon+scale+chain+mail+eva

[beate]

Originally Posted by aerohead

ld drag table for human-powered vehicles, but it didn't have anything we could relate to your trike.

I think i know that table. It should show an entry of the 2nd generation successor the the 3, namely the Evo-R.

But a sign of the three becoming a classic is that prices are somewhat higher than those of, say a Quest or a Mango of the same age, an despite of that, a three is usually sold within a few days or maybe weeks (unless the price take is completely unreasonable).

For now i'm going to concentrate my efforts still in the front wheel area and then doing some improvements of the roof. . And then improve the stiffness of the drive train ... which is quite a large program for this year.

As soon as the wheel boxes are done i might again do some tests of my tailbox.

[aerohead]

Originally Posted by beate

I think i know that table. It should show an entry of the 2nd generation successor the the 3, namely the Evo-R.

But a sign of the three becoming a classic is that prices are somewhat higher than those of, say a Quest or a Mango of the same age, an despite of that, a three is usually sold within a few days or maybe weeks (unless the price take is completely unreasonable).

For now i'm going to concentrate my efforts still in the front wheel area and then doing some improvements of the roof. . And then improve the stiffness of the drive train ... which is quite a large program for this year.

As soon as the wheel boxes are done i might again do some tests of my tailbox.

I checked my human powered vehicle performance table, and for trikes, could only find VECTOR:
68- pounds ( approx. 30.9 kg )
27-inche rear tire ( 675mm )
24-inche front ( 609.6mm )
Cd 0.11
Frontal projected area= 4.56-square-feet ( 0.423 meters-square )
CdA 0.5-square-feet ( 0.0464 meters-square )
Rolling resistance coefficient (Cr) 0.0045
------------------------------------------------------------------------------------
Fachsenfeld's 1951 book shared results from symmetrical wing testing he and Kamm performed at the FKFS.
With an airfoil of 21.3% thickness, the drag coefficient varied from 0.58, with zero aft-body, to 0.065, with the complete tail, in a drag table illustrating six different 'Jaray-type' tail length iterations.
Kamm-type truncations demonstrated remarkably-higher Cds at the same fraction of total tail lengths, except the final, full-length tail, which is identical to the Jaray-type.
It will be interesting to see how the tailbox contributes to the performance.

[beate]

That latest tailbox must have had a real aerodynamic problem - i did not notice anything significant.

BTW: here You see the latest state of the wheel housings - carbon fiber covers are underway:



The gap is intentionally the space for the outgoing vortex, and You might see that the bottom of the wheel house is also closed (with noticeable effect, and done last winter).