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-   -   2017 F150 has front wheel air curtains (https://ecomodder.com/forum/showthread.php/2017-f150-has-front-wheel-air-curtains-34805.html)

Frank Lee 01-22-2017 09:55 PM

2017 F150 has front wheel air curtains
 
http://i146.photobucket.com/albums/r...psejz6zmtv.jpg

Took pic in dealer showroom a few weeks ago.

Trucks also have shuttering grille blocks.

freebeard 01-22-2017 11:09 PM

Now if they could just get the wheel up behind the aircurtain so it does some good...:confused:

Hersbird 01-23-2017 12:13 AM

Ford is really ahead of the others IMO on almost all fronts. Fiat is killing the Ram by comparison. Besides dropping an outsourced diesel (which could end up costing them hundreds of millions) what has Ram been doing lately? GM has some improvements but look at the new Raptor, the new 10 speed, the new aluminum, they have a 5.0 Ecoboost on the horizon for crying out loud. My brother's 2015 F150 seems like a luxury car, muscle car (it will run mid 14's in the 1/4 mile), and tow beast (it has about the same tow rating as my old 2500 Duramax) all wrapped in one and it's only an upgraded XLT trim, they seem built really well.

kach22i 01-23-2017 08:34 AM

Quote:

Originally Posted by freebeard (Post 532767)
Now if they could just get the wheel up behind the air-curtain so it does some good...:confused:

Poises the question, can an air-curtain be used in other locations, and on other openings?

Perhaps at the C-pillar on coupes/saloons?

Hersbird 01-23-2017 10:41 AM

Quote:

Originally Posted by freebeard (Post 532767)
Now if they could just get the wheel up behind the aircurtain so it does some good...:confused:

Maybe the air curtain makes more sense in this application because you can't have tight wheel gaps on a truck with a lot of wheel articulation. The air curtain helps the most right where it is. I don't know just thinking.

freebeard 01-23-2017 03:37 PM

No doubt there is more opportunity than a stanced BMW.

It's interesting to contemplate whether there is more or less churn in a wheelhouse cavity that hardly has a wheel in it.

And there's no opportunity to articulate it with the wheels face anyway.

Hersbird 01-23-2017 06:39 PM

I wonder if it helps or hurts road spray?
Aerodynamic Designs Help Cut Water Spray - Article - TruckingInfo.com

Frank Lee 01-23-2017 07:30 PM

Re: Road spray (worthy of it's own thread): Dumb S.O.B.s at MNDoT have been cutting center- and fog-line "rumble strips" into the roads... to save lives... because dumb em effen Minnesotans can't be trusted to know where the middle of the road is and stay on their side. :rolleyes: :mad: :mad: :mad:

These aren't the old-school tar strips laid on top. Oh no, they have a pavement cutter than cuts mile after mile of divots into the surface:

http://i146.photobucket.com/albums/r...psjfsyshwb.jpg

Since they've been doing this I've had an exponential increase in rock chips and road splash being kicked into my windshields from passing vehicles. Now, I don't mind being passed but it does irritate me more than a little when the dumb bastids think they need to cut back into the right lane as soon as they've put about three feet between their rear bumper and my front.

So, yeah, rocks. Two mechanisms: jarred loose from their uuuuundercarriage when vibrating over those divots and/or those divots collect rocks and water and debris which is then kicked up by their tires.

Even if the roads are dry, if it rained earlier in the day and the divots are full of water, that isht gets kicked up just like if the whole road is soaked.

Plus nobody can be expected to squeeze their phat asses into mere sedans and coupes these days so with all the SUVs and PUs we have bigger tires with more aggressive treads sticking further outta the wheelwells followed by wakes the size of barns so that alone also increase the amount of rocks, water, and other miscellaneous debris being kicked up vs the old days.

Also it is my understanding that the failure mode for pavement is when it collects moisture and that moisture freezes and expands, breaking the pavement up. These water collecting divots seem to me to be a perfect way to guarantee prematurely broken-up pavement. :mad:

I called MNDoT with my concerns but haven't heard back yet.

Re: F150: I'd like to know the Cd and how much these two tricks improved it.

Hersbird 01-23-2017 09:04 PM

Those cuts are terrible. On that note, We have them on the white line side and I have been known to creep over there to pick up some muddy spray for the tailgater behind me. Didn't think there might be some bonus gravel in there as well. LOL!
They have the reflective dots or wedges glued on to the center lane down south. I remember the first time I saw them I asked my dad why we didn't have them back in Montana. He said because there would be plows full of them every winter.

kach22i 01-24-2017 08:08 AM

Quote:

Originally Posted by Frank Lee (Post 532820)
Now, I don't mind being passed but it does irritate me more than a little when the dumb bastids think they need to cut back into the right lane as soon as they've put about three feet between their rear bumper and my front.

They give you a whole three feet in MN?

I've grown accustomed to letting off the gas and maybe braking to get my three feet in MI.

As far as spray from tires, start at the source, and work from there.

Right?

Carbon Sport Performance Concept - Technical & Hardware
http://www.carbon-sport.co.za/produc...ics/aero48.jpg

freebeard 01-24-2017 12:52 PM

Quote:

Right?
No. There are pronounced jets the exit between the front of the tire and pavement, perpendicular to the direction of travel.

kach22i 01-25-2017 08:07 AM

I'm looking for a GIF or CFD still of the pressure and air flow of a car tire in a wheel well.

All I found is some related stuff so far.

AERODYNAMICS OF A SOAP BOX WHEEL
Aerodynamics of a Soap Box Wheel
http://derby.mypalmer.com/techinfo/d...s/wheelhop.gif
Quote:

The aerodynamic behavior of a derby wheel is important because four wheels rotating at high angular and linear velocities disturb a lot of air. The amount of energy required to move anything through air increases in value by the third power of the velocity of the object. (Not to be confused with the increase in drag - Drag increases with the square of the speed.)
Yokohama Puts Spoilers on Tire Sidewalls for Better Aerodynamics
Yokohama Puts Spoilers on Tire Sidewalls for Better Aerodynamics
http://roa.h-cdn.co/assets/15/42/1444924275-tires.jpg

EDIT-1:
Some very nice cartoon-like graphics in this link below, the side view mirror one is awesome.

http://www.buildyourownracecar.com/r...cs-and-design/

EDIT-2
http://pulpaddict.com/tag/lap/
http://pulpaddict.com/wp-content/upl...tantaneous.jpg
Quote:

The image on the left, taken from Jacques Heyder-Bruckner‘s PhD research on wing-wheel interaction, vividly illustrates how the time-averaged image (top) smears away much of the structure associated with the breakdown of a front-wing endplate vortex (bottom).
Source of the above:

The aerodynamics of an inverted wing and a rotating wheel in ground effect

http://eprints.soton.ac.uk/207263/

You can download the doctoral PDF from the link above. It's open-air with wing stuff, not enclosed wheel stuff.

page 33
Quote:

1.2.2 Wheel Aerodynamics
A wheel is a bluff body and as mentioned above, 40% of a Formula One car's drag is
produced by its wheels. The ow behind bluff bodies is known to be unsteady and to
exhibit strong three-dimensional properties [19]. Racing car wheels have the added com-
plexity of rotation, which makes experimental measurements that much more dicult.
Also, the wheels deform considerably under load, their temperature changes and this
would a ect the ow around it. The experimental and computational studies of the ow
around an isolated wheel are reviewed below and it can be noted that there has been an
increase in the research of wheel aerodynamics in recent years
Go to the source to read it, a bunch of missing letters when doing a Copy&Paste.

Frank Lee 01-26-2017 05:02 PM

Quote:

Originally Posted by Frank Lee (Post 532820)
Re: Road spray

http://i146.photobucket.com/albums/r...psjfsyshwb.jpg

I called MNDoT with my concerns but haven't heard back yet.

Gave MNDoT a week to gather their thoughts and called 'em back just now.

They have bought into a "Towards Zero Deaths" paradigm and if centerline rumble strips reduce head-on accidents by "up to 40% AND SAVE LIVES" then that is what they are "pro-actively, systematically" gonna do, regardless of the downsides of increased road debris/spray kick-up, noise, cost, and pavement degradation.

At least I got those concerns on the radar now; the spray/kick-up thing WAS NEVER A CONSIDERATION. At. All. Before now. :rolleyes:

They did pay a bit of lip service to pavement degradation but claim it's inconclusive as to whether water-retaining divots diminish pavement life or not. :confused: Well, time will tell on that one.

Grant-53 01-26-2017 07:33 PM

We have the rumble strips here but not the problems you seem to have. Hard to tell from the photo but I think ours are closer together. Back in the '70s the SAE Journal had a paper on truck splash fenders. The sides of the fenders were about four inches and the rear section tapered like a ramp. Never saw them on the highway.

Frank Lee 01-26-2017 07:58 PM

MNDoT admitted that some contractors cut their divots more than 2x design depth! :mad:

Yep they are aggressive.

freebeard 01-27-2017 12:04 AM

Quote:

Originally Posted by Frank Lee
Re: Road spray (worthy of it's own thread)

I think it is instructive of how the wheelwell turbulence is handled. I've seen some trucks on the freeway in the rain that apparently have an 'anti-curtain' that is sucking a jet outward for a foot from the whole opening.

slowmover 01-28-2017 07:32 AM

The divots are great for what they are designed to do. Same as highly reflective striping. Roads are far better than fifty years ago. Try a windy day and an unruly vehicle.

Now, on the subject of too many road signs, I'd be inclined to agree.

The "curtain" is sure interesting.

skyking 01-28-2017 09:06 AM

Those divots are annoying and they absolutely do result in some shortening of pavement life, especially in the northern states. On Highway 30 in Oregon, between St .Helens and Astoria, the fog lines appear to be a machine formed paint with high frequency shallow grooves. It is unmistakable when you wander onto them.
My chihuahua cross dog is hilarious with road bumps. She sits up on the console, and if I hit a turtle or anything like that her radar ears perk up and point right down at the floor, and then she jumps down by my wife's feet to go check it out. EVery time!

Shepherd777 02-18-2017 09:48 PM

Quote:

Originally Posted by Frank Lee (Post 532764)

Quote:

Originally Posted by freebeard (Post 532767)
Now if they could just get the wheel up behind the aircurtain so it does some good...:confused:

Does anyone have an opinion regarding using vortex generators on the outside of the leading edge of the wheel well, in lieu of air curtains?

It may not help on this F150, but on a vehicle where the leading edge and the trailing edge are on the same plane, i don't know why that would not help the aero.

freebeard 02-19-2017 08:51 AM

There is some discussion at 4:30, here:
https://www.youtube.com/watch?v=aCXTVpj1Ci4

kach22i 02-19-2017 09:31 AM

Quote:

Originally Posted by Shepherd777 (Post 534654)
Does anyone have an opinion regarding using vortex generators on the outside of the leading edge of the wheel well, in lieu of air curtains?

I had coffee with an aerodynamicists couple of days ago.

I would hate to misquote my new friend, but this very idea was proposed as a substitution for wheel spats in a conversation I had with this freelance aerodynamicists. That was one topic on the underside, we also talked about the sides.

Something akin to vortex generators can be used just before a front wheel opening to trip up the air into a smoother air flow over the wheel opening - at least that's what I think he implied.

He showed me some of his work, one example was of an CFD video of a wheel he was hired to examine and determine it's aerodynamic behavior.

He has past experience with several major automobile manufacturers, but has been on his own for a few months now.

SIMSPADE LLC

I trust you can work something out if you want specific answers to your specific design questions.

EDIT:
There was also a recent forum discussion on a similar topic, some opinions expressed.

http://ecomodder.com/forum/showthrea...a-34854-2.html
http://www.mulsannescorner.com/AudiR...st2016-SC3.JPG

freebeard 02-19-2017 04:07 PM

I'd forgotten that example. The difference to the dive planes is that they aren't canted as you'd expect a vortex generator to be.

I guess it's like fences on a diverter, channeliizing the air so one large vortex doesn't form, which would carry energy further away from the surface.

freebeard 02-24-2017 02:40 AM

OP's pic:

http://i146.photobucket.com/albums/r...psejz6zmtv.jpg

I was driving in the rain on a two-lane road a few days ago. I saw a Ford truck with this sort of stance and the spray off the face of the wheel was minimal, but there was a decided jet coming out of the open top. This would suppress that.

Also, where most of the big rigs punched a small hole in the air, I met one that had spray three lanes wide — his, mine and the ditch. It was past by the time I wondered what sort of setup it was.


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