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Old 08-21-2012, 07:31 PM   #11 (permalink)
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Hey the Thanks button works!

I like the motto, as as even though it was coined after the Tillamook Burn, it is way political today.

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Old 08-24-2012, 02:54 AM   #12 (permalink)
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larrybuck -- As promise a *crude* representation of the fender detail.
I was wondering about this for a project of mine. With a cycle fender that moves with the tire, you could get get the gap near zero. Is there an optimal gap for the least drag?

I'm thinking about the airflow strictly within the fender. With the fender stationary and the tire surface moving at high speeds I would guess that getting the gap too small could mess up the establishment of boundary layers and increase drag. Or could this disruption reduce drag?
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Old 08-24-2012, 01:13 PM   #13 (permalink)
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Boundary layers on a spinning tire? C'mon man. We've got bigger fish to fry, one of them being converting that Beetle into Jaray's unrealized wet dream- an aero-improved Tatra T77A (probably my favorite car). It's already got good plan taper so tub the rear wheels and make flush skirts for the wheel wells. Raise that rear bodywork up to match the template. And a center headlight!

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Old 08-24-2012, 10:26 PM   #14 (permalink)
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drkarrow -- Actually, you are correct, sir. When they want to stress test motor oil (ferinstance), it is put between two close-fitting concentric cylinders that are spun against each other. It can rip the molecules apart. In this case the boundary layer is your friend. But still, what Sven7 said.

Sven7 -- Imagine the Beetle's backlight about where the middle of the Tatra engine is:
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Old 10-14-2013, 01:49 AM   #15 (permalink)
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I'm resurrecting an old thread, because this story in the news caught my attention.

Protean unveils production in-wheel electric drive system

Wiki here: Protean Electric - Wikipedia, the free encyclopedia

Company here: Protean Electric | Protean Electric

Similar tech discussed on Ecomodder here: http://ecomodder.com/forum/showthrea...tml#post318890

In fact it's mentioned directly at http://ecomodder.com/forum/showthrea...tml#post348568. I'll post there as well.

The Protean Direct Drive has some interesting tech, a low-speed/high-torque design with integral multiple micro-inverters. This would enable the design I modeled in the mid-1990s.



I know, I know, ...open wheels..., blah, blah, blah. At this point I think it would have a Baja'd nose, and a Speedway dropped-tube axle with a U-shaped diverter/fender like the Mercedes Benz Silver Arrow.



Back to the motor[s]:
  • 4.5" thick, 16" in diameter and ~100 horsepower
  • A commercial product on the market in 2014
  • Requires an 18" wheel and is geared for 1000-1500rpm
  • reference controler code for evaluation testing
  • communicates via CAN bus

Torque is dropping fast at 2000rpm; or, say 150mph without taller tires. Their videos suggest the motor has an open center so a driveshaft can pass through. Can a differential for inboard mounting be far behind?
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Old 10-14-2013, 08:48 AM   #16 (permalink)
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Though they don't use in-wheel motors, the concept of using the idle rear wheels on FWD cars in hybrids is already being commercialised by Peugeot / Citroen and Volvo.
(Taking clues from the ancient Porsche, no doubt.)

In wheel motor are just the next step.
Though it's more of a technological jump than a step.
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Old 10-14-2013, 09:17 AM   #17 (permalink)
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I'm resurrecting an old thread, because this story in the news caught my attention.

Protean unveils production in-wheel electric drive system
Good story. Thanks. I sometimes daydream about those lonely wheels dragging behind me ...

I think they're smart to make China the first primary target market. Lots of electric stuff on the road there, and the smog problems are unbelievable.
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Old 10-14-2013, 02:29 PM   #18 (permalink)
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Quote:
In wheel motor are just the next step.
Though it's more of a technological jump than a step.
The Porsche example suggests it's a reversion. I read once why it fell out of favor, but I don't remember where or why.

California98Civic -- Would you put 18's on the front too, so they match?

One unit weighs 68lb and is rated at 100hp (72hp continuous). Two seems excessive to me, but it occurs to me that you could mount two on either side of the VW Type I (or Subaru) transaxle similar to inboard disk brakes. With 50-250hp through the tranny and 200hp from the electric hybrid (supercapacitors to save weight) it would have supercar power/weight ratio and performance.
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Old 10-14-2013, 08:55 PM   #19 (permalink)
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The Porsche example suggests it's a reversion. I read once why it fell out of favor, but I don't remember where or why.
At the time, the electric motors were large and heavy and not that efficient. And batteries were incredibly massive and also not very efficient. I remember reading recently that the Porsche-Lohner "Mixte" weighed in at something like four or five tons?

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Old 10-14-2013, 11:59 PM   #20 (permalink)
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I was on the phone with my brother, suggesting when these are on the market he replace the front brakes in his 1946 Ford pickup—with no batteries, just capacitors. Stock Ford flathead drivetrain and rear brakes with a Kinetic Energy Recovery System.

Maybe 200lb added less the weight of the stock front brakes.

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