Random Aerodynamic Oddity of the Day Thread

[freebeard]

BD-5 flight trainer


https://i.pinimg.com/236x/9f/ad/e2/9...20d9cfcc09.jpg

I always liked the BD-5.

[kach22i]

Originally Posted by freebeard

I always liked the BD-5.

Me too, but Burt Rutan's designs have a much better safety record.

Even Burt could not fix Jim Bede's design.

Maybe it was a design only Les Berven could fly?

Bede BD-5
https://en.wikipedia.org/wiki/Bede_BD-5

2012
Micro.
Little jet, big impact
https://www.aopa.org/news-and-media/...er/pilot/micro

“It was a beautiful little airplane, but engineering-wise, it was a mess,” Rutan recalled. As the basic aerodynamic problems with the original piston-powered, pusher-prop BD–5 were solved, Rutan moved to the jet version, and recalls playing a key role in the adaptation. It also provided Rutan’s introduction to Herb Iverson, who worked for the French turbine maker Microturbo that supplied the first-generation jet engines. The two would go on to found Scaled Composites. Rutan left the BD–5 project in 1974, returning to California as it became clear to him the company was headed for disaster.

[Bicycle Bob]

Richard Bach didn't complain about his BD-5 jet's handling.
Bede was keen on aircraft, but his talent was in sales. During the long grind looking for a new piston engine, the prototype had never flown with less than 20 lbs of lead in the nose. Asked about it, Jim feigned total surprise at the notion of putting weight into an aircraft.
There was a meeting with dozens of impatient builders once, and someone tried to warn Jim that they might do him harm. Two hours later, he had them eating out of his hand again.

[kach22i]

I noticed this little detail in a parking structure last night.

Honda CRV with a clean release edge for the air leaving the body.

https://www.bernardiparts.com/Honda-...-TLA-XXX1.aspx


Maybe one day it will not be such an oddity.

[freebeard]

http://www.remarkablecars.com/for-sa...75/06510-2.jpg

Maybe someday we'll have full-blown skegs and Turnpike Cruiser fender skirts.

[kach22i]

Random TRANSPORTATION pictures - Page 2045 - Pelican Parts Forums

...........variable inlet geometry.........

ECS (Environmental Control System) ram air inlets on a 747:

[freebeard]

The movable part is in the floor? Is it hinged at the front or back (stopper or secondary inlet)?

[Piotrsko]

You sure that's ECS? I thought they used bypass bleed from #2,#3

[kach22i]

Originally Posted by Piotrsko

You sure that's ECS? I thought they used bypass bleed from #2,#3

The guy I quoted in that other forum is a BS artist, would not take anything he said at face value.

Would not be surprised at all if he was wrong and just making stuff up.

Maybe I should remove the caption?

Anyway, a variable geometry NACA inlet would be an oddity in my opinion.

Not sure why they wouldn't regulate flow via outlet, but there must be a reason other than job security, right?

[Bicycle Bob]

Bleed air from the engines is handy for cabin heat. Ambient air is probably needed at lower altitudes, where ram would help before cabin pressurization kicks in.
It is nice to see a NACA duct used well, after all the odd placements on cars. The variable opening is a nice enhancement, although it probably works best at the textbook proportions. The shape certainly lends itself to simple sliding adjusters.