Solution to boat tail dragging On Ramps

[Xist]

At least this OP reports back, unlike the guy who started that argument about scientific consensus or whatever.

[Angel And The Wolf]

Originally Posted by Angel And The Wolf

Yes, Beard, but F1 cars have high drag, and are about downforce at the expense of mpg.

This from schumiGO on F1 CD

"F = 1/2 * rho * Cd * A * V^2
I don't know exectly situation now but in 2000 and 2001 in soe track not so fast and slow maclaren has Cd that used in F = 1/2 * rho * Cd * A * V^2 formula near 0.67 and 0.65
So now it must be a little mort 'cause aero rules had been changed..
So now range [0.75:1.25] is realy possible."

https://www.f1technical.net/forum/viewtopic.php?t=1861

[freebeard]

Soe track...mort...realy?

Originally Posted by Xist

[Mr.-sic] freebeard uses the English language differently than the rest of us. I am pretty sure he makes up half of the terms I do not know!

You're making me think about F1 more than I wanted to (it's sunny outside), but let's ask http://formula1-dictionary.net

Very low drag to downforce ratio is important to take into consideration during design. Underbody is working in very close relationship with front wing and splitter in the front of the car (feeding the air to underbody) and diffuser on the back (extracting the air from under the car).

Now I'll need to read up on stepped planes and barge boards.

[Angel And The Wolf]

Originally Posted by freebeard

Soe track...mort...realy?
You're making me think about F1 more than I wanted to

]

Guess I should have used *sic* more. That was all quote from the URL I included.

[freebeard]

No slight intended. I was using it as a counterpoint to Xist.

What's your current thinking on adding a bustle to the Prius?

[Angel And The Wolf]

A WHAT? I'm not familiar with that term.

[freebeard]

Once again, baiting Xist. Sorry [to both]. Multiple layers of meaning

bus·tle 1 (bŭs′əl)
intr. & tr.v. bus·tled, bus·tling, bus·tles
To move or cause to move energetically and busily.
n.
Excited and often noisy activity; a stir.
[Possibly variant of obsolete buskle, frequentative of busk, to prepare oneself, from Old Norse būask, reflexive of būa, to prepare; see bheuə- in Indo-European roots.]
bus·tle 2 (bŭs′əl)
n.
1. A frame or pad to support and expand the fullness of the back of a skirt.
2. A bow, peplum, or gathering of material at the back of a skirt below the waist.
[Origin unknown.]

[Angel And The Wolf]

OK, I went ahead and checked, and the profile averages 15 degrees where it would apply to a boat tail:

[Angel And The Wolf]

I'm looking into a way to direct a 48" wide x 4"tall under bumper air scoop to a 12" wide by 16" tall exit under the Boat tail, with the idea that throughout the passage under the boat tail, any cross section will be 192 square inches, thus maintaining an equal pressure, and hopefully preventing the low pressure area that would draw the tail down Drawing to follow

[freebeard]

I gave that my best shot at Permalink #24 with the half-bell. Think about a NACA duct. Vortexes generated by the curvature of the duct sides pulls air down into the throat of the duct. This acts like a reverse NACA duct, pulling underbody air in toward the center and up into the bell.

For balance, here's a different approach, from Bonneville:



This is also a bell — the roof has some curve to it. But it progresses from the full width, narrow inlet to an outlet that is ~4-5x the opening. I think this slows the air down and decreases it's static pressure to match the wake. But... I'd want to get aerohead's opinion on whether that's even wrong.

and again:

2nd from the top left is the High Momentum Mudflap. It's boat tail shaped.