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

[aerohead]

You may also want to dig up NASA's 'Large Eddy Break Up device,investigated for aircraft fuselage many years ago.I don't remember that they had any success with it,but the more info the better.

[ChazInMT]

I hate to be a wet rag on your fire here, but keep in mind that these winglets you are discussing are all fine tuning enhancements on vehicles which are very aerodynamic to begin with. They effect only a small amount of airflow around the vehicles. Putting these things on a pick-up truck which has the aerodynamics of a shaped brick is IMHO a waste of time and energy. You need to do things that affect mass amounts of air in order to see anything that is going to make an appreciable difference. Building a 2 ft kamm sorta thing on the front of your cargo box would probably net you the biggest easiest gain, a full on aerocap, would be better yet. Anything you do will be optimized by following the template.

Just sayin.

[kach22i]

Originally Posted by ChazInMT

I hate to be a wet rag on your fire here, but keep in mind that these winglets you are discussing are all fine tuning enhancements on vehicles which are very aerodynamic to begin with. They effect only a small amount of airflow around the vehicles.

I can appreciate your point, it is a good one. I must have my fun trying the weird and implausible before surrendering to the tried and true.

From a post/thread back in 2004 talking about "LEX Fences" and such.

Question for the Aero Experts - Page 2 - Pelican Parts Technical BBS



I did some highway driving today, the thought of attaching 24" long x 6" dia. PVC tubes at the edge corners on the roof and at the tail of the bed top came to me. The idea would be to tunnel/tube shoot some ram air where vortexes would normally start to form. Not my best idea, but I go though a lot of them. Then one day the urge to build slams me and I do something nutty and rather spontaneous.

Stay tunned.
http://s184.photobucket.com/albums/x...4%20Pick%20Up/


The tube idea really started as a pod idea, sort of F-104 and Caddy Tail Light.

http://ckparis.blogspot.com/2009/05/...-fins-and.html


http://s184.photobucket.com/albums/x...4%20Pick%20Up/


EDIT 12/16/11
I found a patent somewhat similar to the trail edge/corner thing I've been thinking about. Again, a wing, and not a box (truck cab).

http://www.wikipatents.com/US-Patent...ing-tip/Page-1


http://www.britmodeller.com/forums/l...hp/t72943.html

[sc2dave]

Originally Posted by kach22i

IIRC, those fins you refer to as LEX fences are called vortex generators.I worked on these F/A-18 jets in the service back around '91

[Frank Lee]

200 lbs of downforce? I suspect that if I pressed down on that wing with 200 lbs of force you would hear your roof rippling.

[kach22i]

Originally Posted by sc2dave

IIRC, those fins you refer to as LEX fences are called vortex generators.I worked on these F/A-18 jets in the service back around '91

Read post #28
Question for the Aero Experts - Page 2 - Pelican Parts Technical BBS

You are right.

The concept or lesson here is that vortexes can be tools and do a job.

[kach22i]

Originally Posted by Frank Lee

200 lbs of downforce? I suspect that if I pressed down on that wing with 200 lbs of force you would hear your roof rippling.

I know what two, 65 lbs (130 lbs) of tube sand feels like over my rear axle.

I drew a diagram and stated that the increased down-force was because the rear spoiler was made more effective.

What part do you not understand Frank Lee?

[Frank Lee]

I guess that's the part I did not understand! Well, it takes 20 min for all those quoted pics to load.

[viio]

Did you ever get this thing modelled in CFD? I could knock something up for you?

[kach22i]

Originally Posted by viio

Did you ever get this thing modelled in CFD? I could knock something up for you?

No I did not. Real life and seat of pants only, which is best, right?

I would be curious to see if CFD could handle the tiny air gap between roof and wing.

Do it up, I'll owe you a beer.