Roof Spoiler on Pick-Up Truck Cab - Phase-1

[kach22i]

Originally Posted by ChopStix

Did you buy this PDF as your influence for your pickup wing project?

No purchase, I'm too cheap for that.

I suspect the Chen solution linked to is similar to the yellow section diagram on page one of this thread.

My 1976 Ford E100 shortbox (orange with black tiger stripes plus chin spoiler) had a rain gutter all the way around if I recall correctly (+30 years ago 1983-ish ).

Perhaps you will want to cut and pull back to horizontal the rear roof drip edge for starters. The clean release of air would be nice, plus you can easily extend it Bonneville style.

With a van the best thing you can do is make sure your tires are properly inflated, such is the life of a brick through the air.

REPOST on air slots and slats..........so I can find it later.

Do leading edge air slots/slats alter the story line?

Wing Design - Level 3 - OTHER WING ADDITIONS


NB1 BMW ACS Style Roof Spoiler - BMW E90 3 Series Coupe


Porsche


http://zenithch801buildlog.blogspot....dge-slats.html

And in this picture again as above with the air path moving further rearward on the wing. The purpose of the leading edge slat is to accelerate the air across the top surface of the wing hold the boundary layer against the wings top surface in high angle of attack manouvres which prevents the stall allowing a much greater critical angle than a standard wing section (without the slat).

http://www.homebuiltairplanes.com/fo...dge-slots.html

[aerohead]

Especially in the last image,the authors need to qualify the flight envelope for the pictured wing.
Up until a certain velocity,there would be no 'compression' of the air,only acceleration,and an attendant pressure drop.
On automobiles this would be 250-mph.
Fixed-slats and slots are of the highest drag configuration for a wing.
The Fieseler Storch,with almost helicopter-like STOL characteristics has one of the highest drag coefficients measured for an aircraft.

[gumby79]

Is the 250mph a local air velocity or movement speed ?
In the A&P study book it was talking about the slats& flaps were retractable for low angle of attack flight,not a speed but angle thing.
---YOU SEE the same principles applied to the front as a air curtain to maintain attachment past the front tires. And theas work at normal people road speeds (well below 250)

The 1/8" ×3" flat strap was added to keep ladders and 20'sticke of steel off the sheet metal roof. An top hafe air foil was carved for the top surface (that was set @0° level). But it snaped when I was bending into shape. I think the flat strap helps restableize the turbulence from the cab-bed gap, and redirect it down the cap
Gumby Stay Flexible

[kach22i]

Originally Posted by gumby79

....I think the flat strap helps restableize the turbulence from the cab-bed gap, and redirect it down the cap
Gumby Stay Flexible

I see some of your other angles.

Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - gumby79's Album: Jona 1991.5 Dodge d250pickup



It's going to take me a while to figure this one out.

Have you driven around without the red foil, cap/top only?

[kach22i]

Originally Posted by aerohead

Fixed-slats and slots are of the highest drag configuration for a wing.

That I'm sure is true, but a notch-back coupe is a magnitude larger source of drag compared to even the worst slotted wing.

If one could get a notch-back coupe or pick-up truck to manage the air flow off the roof in any manner and by any means and improve upon the stock configuration, then I say go for it.

My seat of the pants testing says the roof wing works, I encourage others to give it a try and see for themselves.

We are going to see more and more of these air-diverters and air management systems fitted to cars and trucks in the future, best we make some attempt to understand them.

[aerohead]

Originally Posted by gumby79

Is the 250mph a local air velocity or movement speed ?
In the A&P study book it was talking about the slats& flaps were retractable for low angle of attack flight,not a speed but angle thing.
---YOU SEE the same principles applied to the front as a air curtain to maintain attachment past the front tires. And theas work at normal people road speeds (well below 250)
Attachment 20218
The 1/8" ×3" flat strap was added to keep ladders and 20'sticke of steel off the sheet metal roof. An top hafe air foil was carved for the top surface (that was set @0° level). But it snaped when I was bending into shape. I think the flat strap helps restableize the turbulence from the cab-bed gap, and redirect it down the cap
Gumby Stay Flexible

*It would be the road speed,as the body of the car could generate local velocities (especially over the roof) of the transonic range.
*Retractable slots/slats would be a necessity unless you were doing a homebuilt copy of a Storch,which it's design mandated the fixed air dicers.
*The upper wing camber of of a cargo spar would be good! It's at zero angle of attack,and zero lift,just like a Clark-Y (Hershey Bar) wing on a Piper Cherokee.
*Curving the strapping would produce lift,and you would have a downwash towards the cab roof.There might be a point where the strapping became aeroelastic and begin to deform into a flutter mode,ultimately destroying itself unless dampened by some sort of structural support.

[gumby79]

I used 1/2" ×1/8" flat strap@1/3 interval on edge (frontal area of 1/8"×2"=.25 sqin per support ×4 , ~8" solid weld front and rear in the center and .095 1"×3" rectangular steel for the uprights

[aerohead]

Originally Posted by kach22i

That I'm sure is true, but a notch-back coupe is a magnitude larger source of drag compared to even the worst slotted wing.

If one could get a notch-back coupe or pick-up truck to manage the air flow off the roof in any manner and by any means and improve upon the stock configuration, then I say go for it.

My seat of the pants testing says the roof wing works, I encourage others to give it a try and see for themselves.

We are going to see more and more of these air-diverters and air management systems fitted to cars and trucks in the future, best we make some attempt to understand them.

There's not a great deal of data on roof wings.
The late 60s AMC Javelin was tested.It's rooftop wing didn't do anything.
One of the Toyota Celica Supra's was tested.It's rooftop wing was useless as well.
This might be it,Cd 0.348


The Mercedes-Benz 190 EVO had a combo much like the Lancer,with roof trailing edge deflector and trunklid-mounted wing which helped with stability.I don't know about drag.
The Texas Tech truck wing was non-aspirated so it wasn't really a 'wing',as used in normal parlance.
Here is a Ford iteration of their Texas Tech creation

Kind of an embryonic/vestigial wing on this concept

Another non-aspirated 'wing'


The looming CAFE standards may spell the end for 'hard' notchbacks.Even Subaru has evolved the Lancer with a 'sportback' greenhouse.

[kach22i]

Originally Posted by aerohead

There's not a great deal of data on roof wings.
The late 60s AMC Javelin was tested.It's rooftop wing didn't do anything.
One of the Toyota Celica Supra's was tested.It's rooftop wing was useless as well.

Thanks for the info, didn't think about the Javelin - rare.

AMC Javelin SST 390 Mark Donohue : 1970 | Cartype

Less than 200 AMC Javelin SST 390 Mark Donohue editions were produced, and this one is 1 of only 3 registered in the USA.

The Lancia Stratos wing is pretty tiny too.

Race Car Spoiler Related Keywords & Suggestions - Race Car Spoiler Long Tail Keywords


Just about every SUV make and model on US roads has a roof wing, roof spoiler or at least a lip, so I'm sure the data is out there. Just maybe cutting edge and proprietary so I'm not going to have access to it.

I'll just have to rely on my pants.

2015 Porsche Macan Review Price Photos | Gayot


http://www.kbb.com/car-news/all-the-...ed/2000011442/


http://www.nissanusa.com/crossovers/....nismo-rs.html



2011 Nissan Juke
http://www.topspeed.com/cars/nissan/...e-ar84837.html

The rear of the roof incorporates an integral spoiler to reduce aerodynamic lift to help high speed stability. The neat duck-tail ridge was perfected with computational fluid dynamics (CFD) and tests in the wind tunnel.

[Xist]

https://en.wikipedia.org/wiki/Merkur_XR4Ti