Random Aerodynamic Oddity of the Day Thread

[kach22i]

Originally Posted by Frank Lee

Traded reduced aero drag for increased rolling resistance?

Rear wheel looks to be conventional with covered spokes.

Front wheel looks to ride on four roller bearings in lieu of a central hub.

I don't know anything about this bike, but research into it's rolling resistance seems warranted.

2010
A hubless wheel from the past: The Black Hole
https://bicycledesign.net/2010/03/a-...he-black-hole/

What better time to revisit a couple of old posts about a hubless wheel, which (I believe) actually went into production for a short time in the mid 90s. The picture you see above is an early prototype of the Black Hole hubless wheel system from “Wear and Tear”. According to the company, this assembly weighed about a pound less than a conventional fork and wheel. Sounds great…why didn’t it catch on?

To the left, you can see a later prototype of the Black Hole. Obviously, the designers were a little too optimistic with that large opening in the previous prototype. I am not sure what happened to Wear and Tear, but I have my doubts that this later prototype was lighter than the average conventional fork and wheel that was available at the time.

2018
The weirdest bike on eBay right now — $15,000 of retro aero tech
https://www.bikeradar.com/features/t...tro-aero-tech/

As revealed in an interview with our frenemies at BikeRumor, the wheel was the first product developed by Paul Lew — a key figure and an influential aerodynamicist at Reynolds Wheels.

As far as I understand, the rim has a track embedded into its inner circumference. This runs on three track rollers that are fitted along the bottom edge of the inner supporting structure. An additional roller sits at the top of this structure to ensure the rim stays aligned.

Ride reports from the time claim that the ride quality of the Black Hole was remarkably normal, though was said to be incredibly noisy, with the whole structure reverberating and amplifying vibrations on rough surfaces.

Performance wise, the system was claimed to have roughly the same characteristics of a disc wheel.

Racing is known banning innovation as soon as it gives one team an advantage over the meritocracy.

In 1994, the wheel was ridden by Bryan Walton on the track in the 4,000m individual pursuit and it was ridden to further success at Kona, setting a number of split time records there.

Performance needn’t have mattered though as, according to the interview, less than 100 units were sold and the wheel system was banned by the UCI not long after launch.

From a link in the above article.

2012
How to Break Into the Cycling Industry – Reynold’s Aerodynamics Expert Paul Lew
https://bikerumor.com/2012/10/25/how...pert-paul-lew/

It took us about three years, and in 1993 we started selling them. It was exciting, but very radical. For most people, it was interesting, but not something they’d buy. In 1994, Bryan Walton, a former 7-11/Motorola/Saturn pro cyclist started working with us and started racing the wheel in the 4000m individual pursuit. Then Jurgen Zack, a triathlete that set the bike split record at Kona several times, was going to race it, too, but the UCI banned it calling it an unfair advantage. So, that was the end of the Black Hole wheel. We shut the company down. We sold less than 100 wheels, but people still have them.

I found this part of the interview interesting.

BIKERUMOR: What’s your educational background?

LEW: In 1985, I got a bachelors of science in mechanical engineering from the US Naval Academy. In 1989 I finished a bachelors of Architecture. The formal education in fluid dynamics, which is a broader category than aerodynamics, pertains to air. For example, when I use the CFD program to design bicycle wheels, I have to choose the medium (air, water, oil, etc.). As far as architecture, prior to learning how to put a structure together, there’s a period where you focus solely on design. The first two years of the program are highly focused on design. We take art, sculpting and drawing classes. We design a lot of things other than buildings. Things like cases for small items, bicycles, medical equipment, etc. Then, that’s integrated into how bricks, steel and wood go together, stress loading and the nuts and bolts of it. It’s a nice way to complement my engineering education. It really helped me with design.

[freebeard]

Originally Posted by eBay

Ride reports from the time claim that the ride quality of the Black Hole was remarkably normal, though was said to be incredibly noisy, with the whole structure reverberating and amplifying vibrations on rough surfaces.

Noise/Harshness/Vibration (NHV) would have killed it if the racing ban hadn't.

[gumby79]

Spotted this Slide-in Camper called a Kimbo kimboliving.comSouthbound on I-15 @the merger of I-84 north of Ogden,Utah





The angles are a little harsh probably more for trendiness, but should be better than a traditional Slide-in

[freebeard]

Everything they gain from the lost interior space they loose to the camper jacks. The faceted shape isn't a big problem; but the ladder on the side and weather stripping that door are.


http://justacarguy.blogspot.com/2019...y-have-to.html

Ditch the tail boom and hook the engine up to a transmission and Ford 9-inch rear end. Maybe a spun aluminum tank on the front?

[kach22i]

Well, in my mind this has something to do with fluidic motion, yes snake-like motion.

Creepy Velox robot uses undulating fins to skate over solid ice
https://newatlas.com/ice-skating-velox-robot/57587/

[kach22i]

An interesting website and blog.

Blog - The Answer is 27



The Answer is 27

Welcome to The Answer is 27, a blog which I expect to be useful to anyone interested in computational fluid dynamics and race car engineering. In this site where I will show my progress and advances in such subjects —what you see above this lines is a selection of my latest entries. There’s much more:

Porsche 944 hatch removal aerodynamics

[kach22i]

Random TRANSPORTATION pictures - Page 2190 - Pelican Parts Forums

[freebeard]

Makes you wonder what the next generation will look like.

[Bicycle Bob]

It also makes me marvel at the difficult history of automotive streamlining, and the hazards of copying shapes. That series shows the importance of downforce, which mandates hard suspensions now, but may lead to load levellers next year. For decades, most attempts at streamlining were inspired by aircraft, where a bit of gratuitous lift is always welcome, and nobody realized why that made the handling tricky. When wings were discovered, Colin Chapman put his right on the hub carriers, but they broke and that was banned. If he'd just added a bit of suspension to the wing, we might still have big wings and slim bodies. We might even have vertical fins to help change direction with, which is the point of all the new drag inducers.
I was a rear-engine fan all my life, until I realized that all fast, light vehicles should be able to enter a stable glide.

[freebeard]

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