A Non scientific everyday Aero Observation

[freebeard]

Originally Posted by aerohead

2) somewhere, east of Eiesenhower Tunnel, on I-70, a pressure ridge spanned the entire lane, and the little trailer wheels acted as if on a Vail ski jump, sending Viking airborne, in a curve, then jerking back into train as the wheels touched down. Very disconcerting!

Something like this?

https://justacarguy.blogspot.com/202...d-that-is.html

[MeteorGray]

Quote: "...4) I've no personal knowledge of light vehicles sent into ditches in response to a commercial vehicle. Hucho devoted an entire chapter to concerns about this sort of thing. In 1990, the first time I went to Bonneville, about 10-miles east of the raceway, a triple-trailer rig was laying on it's side, west-bound on I-80. There's a price for load floors 48-inches off the ground and square-edged trailer sides. ( stupid American manufacturers )
5) empty boxcars would succumb the same way as an 18-wheeler. ( stupid American boxcar manufacturers )...."

The box design is stupid in terms of exterior aerodynamics, but brilliant in terms of construction cost and cargo space utilization.

Every design has its consequences.

Pay your money and take your choice. :-)

[j-c-c]

Originally Posted by freebeard

Something like this?

https://justacarguy.blogspot.com/202...d-that-is.html

So that appears to be a case of the bridge "channeling" the ambient air currents to cause the roll over of the rear, likely lightly loaded trailer, that had a reduced air stream to keep it in line while moving vs say the leading trailer ( a flag in the wind is a decent analogy?), and then the bridge abutment became a useful bumper to correct the unfolding accident, and everything was then right with the world, except for changing the drivers underpants?

Main takeaway, never, never ride alongside a semi.

[aerohead]

Originally Posted by freebeard

Something like this?

https://justacarguy.blogspot.com/202...d-that-is.html

Kinda like it, as far as pulling the trailer back into line. I was glad for the lower C. G., and even though there was no crosswind, the trailer isn't sensitive to that, so not an issue.

[aerohead]

Originally Posted by MeteorGray

Quote: "...4) I've no personal knowledge of light vehicles sent into ditches in response to a commercial vehicle. Hucho devoted an entire chapter to concerns about this sort of thing. In 1990, the first time I went to Bonneville, about 10-miles east of the raceway, a triple-trailer rig was laying on it's side, west-bound on I-80. There's a price for load floors 48-inches off the ground and square-edged trailer sides. ( stupid American manufacturers )
5) empty boxcars would succumb the same way as an 18-wheeler. ( stupid American boxcar manufacturers )...."

The box design is stupid in terms of exterior aerodynamics, but brilliant in terms of construction cost and cargo space utilization.

Every design has its consequences.

Pay your money and take your choice. :-)

Everyone on Earth pays for the 'brilliant in terms of construction costs and cargo space utilization.' Couldn't be more stupid. 'Pay me know, pay me later, just keep paying.'

[aerohead]

Originally Posted by j-c-c

So that appears to be a case of the bridge "channeling" the ambient air currents to cause the roll over of the rear, likely lightly loaded trailer, that had a reduced air stream to keep it in line while moving vs say the leading trailer ( a flag in the wind is a decent analogy?), and then the bridge abutment became a useful bumper to correct the unfolding accident, and everything was then right with the world, except for changing the drivers underpants?

Main takeaway, never, never ride alongside a semi.

Yes, exactly. The trees are gone alongside the roadway to and from the overpass, forming the channel which provided the 'jet' of air.
Flying the Grand Tetons, our light Cessna 310 regularly encountered katabatic winds descending gorges between mountains, and we'd be blown sideways in the jet of colder, denser air, requiring quite a bit of crabbing at times. With an entire, and wide valley to navigate, it wasn't an issue.

[freebeard]

Originally Posted by j-c-c

...and then the bridge abutment became a useful bumper to correct the unfolding accident

I don't think it ever touched the abutment.

[j-c-c]

I agree, I could not confirm the actual contact, but then maybe it was a play of aero "ground effect" on the trailers sidewall from the bridge abutment that helped restore it up right? Something played a part, because it was way past rolling all the way over.

[MeteorGray]

Quote: "Everyone on Earth pays for the 'brilliant in terms of construction costs and cargo space utilization.' Couldn't be more stupid. 'Pay me know, pay me later, just keep paying.' "

Well, it's a shame you didn't go into the trucking and railroad business and showed them how to do it right. I guess it didn't pay enough for you.

How did you make your fortune?

[aerohead]

Originally Posted by MeteorGray

Quote: "Everyone on Earth pays for the 'brilliant in terms of construction costs and cargo space utilization.' Couldn't be more stupid. 'Pay me know, pay me later, just keep paying.' "

Well, it's a shame you didn't go into the trucking and railroad business and showed them how to do it right. I guess it didn't pay enough for you.

How did you make your fortune?

I've followed both industries since 1974. I was at Edwards Air Force Base when NASA conducted their Class-8 and box-truck aerodynamic research, which would have also be germane to the railroad industry.
The best railroad tailcar ,yet to be used in industry, dates to 1865, with Calthrop's patent. While at Westinghouse, in the 1930s, Oskar Teitjens conceived a self-powered railcar of Cd 0.08.
My Aunt and Uncle E.C. Burnett were the very first team drivers for Tri-State Motor Transit, Joplin, Missouri. E. C stayed with them long enough to become an officer, shuttling between Missouri and Breckenridge, Texas in a Beech Baron until macular degeneration robbed him of his eyesight.
In 1980 I pursued US Patents, only to be told that without sufficient capital to prosecute infringers ( $250,000 per case) there'd be no reason for the energy and expense for patents. Venture capitalists won't part with cash without patent protection. The DARPA / SBA small innovative research grant program, which would provide up to $425,000 for proof-of-concept, and initial commercialization had stipulations which carried things beyond the control of an individual, requiring a corporate charter.
Very few of patent holders ever saw industry adoption. A neighbor had three to his credit and never saw a penny.
Going it alone as an amateur is what is left to the little fish. Aerodynamics has pretty much bankrupted me but the knowledge is priceless.
Jaray never made a penny. Hundreds have come and gone. MS or PhD it makes no difference.I don't know why it would be any different for me. If real wealth can't compete with myopic greed and pollution, it can't compete.
Half of American economists can't count. And they're the ones who get to make the big decisions. And the 'externalities' which are absent from the ledger are borne by the voiceless masses.Nice system.