Random Wind Tunnel and Smoke Pictures Thread

[kach22i]

Coanda effect
Coanda effect - Gas Savers - Fuel Efficiency Forum


Car above is here in article:

Renault Altica: 44MPG Diesel Concept with Active Airflow Management

http://www.greencarcongress.com/2006...t_altica_.html

Interesting PDF on that page/link"
http://permanent.access.gpo.gov/webs...01-01-2072.pdf

[freebeard]

I'm very interested in the Coanda Effect for my panel van. As much as I've followed the links so far, the comments are about sizing a fan for wake filling, etc.

What I want to do would be like the chrome sacks on a big-rig truck, except they would be tear-drop shaped, capped with a Bonneville wing at the top and a single or double row of louvers just abaft the separation point, all fed by the tailpipes.

With a big honking motor you could do a complete halo around the rear.

[kach22i]

An interesting diagram intended only to express the concept of lift.

Aerodynamic Tips and Tricks You Can Use for Better Performance - Hot Rod Magazine

Airplanes fly because of lift generated by their wings. Air moves fasterover the wing's upper curved surface (as shown over the roof of thiscar) than the lower flat surface (the air shown under the car). Thefaster moving air creates a localized low-pressure area. With denser airunderneath, lift is generated. Full-bodied production cars are shapedvery much like an airfoil so they have natural lift. Good for anairplane, bad for a car.

I have to admit, the above diagram did remind me of the below diagram.

http://www.gerrelt.nl/section-aerody...planation.html

[kach22i]

New tools to the smoke and tufts arsenal?

The new B-Class: Aerodynamics – Taking the drag out of aerodynamics
The new B-Class: Aerodynamics – Taking the drag out of aerodynamics | Mercedes-Benz Passion eBlog

The aerodynamics of the new B-Class were optimised at an early stage in the development process by means of complex computer calculations and flow simulations. Over 275,000 CPU hours were required for the purposes of digital flow simulation. Models and prototypes spent around 1100 hours in the wind tunnel for measurement purposes.

[kach22i]

Mercedes-Benz premieres Aerodynamic Truck and Trailer

[freebeard]

I'm curious about the air scoop on the side of the rear diffuser.

The M-B modelling is awesome in the way it shows the flow around the rear profile and at the wheelwells. Can't wait for the movie.

Over 275,000 CPU hours were required for the purposes of digital flow simulation.

That's like 1024 cores for 10 days straight.

[kach22i]

I found a rear view of a similar series truck - see attached far below.

I think it's a vent similar in function to the VW GTI project.

Volkswagen Golf GTI W12
Volkswagen Golf GTI W12 650 volkswagen-golf-gti-w12-650-16

[kach22i]

New VW Polo [Site Map] - SportsCarForums.com

New VW Polo [Site Map] - SportsCarForums.com


Andoniscars | passion for excellence

[aerohead]

At posted speed limits,you can't legally drive faster than 85-mph (between Austin,Texas and San Antonio,Tx.) in the USA.
In 1969,a GM Pontiac GTO "Judge" was road tested in the Nevada desert.
At 115-mph,the car,without the rear spoiler,generated 105-lbs front lift,and 250-lbs rear lift.
Those testing the car felt that due to the car's weight,none of this lift was an issue for stability.
Since these forces vary as the square of the velocity,even at 85-mph across the 41-mile stretch in Texas,this lift would be virtually meaningless.
Hopped-up,and at El Mirage or Bonneville,yes,but not in everyday highway commuting.

[kach22i]

Originally Posted by aerohead

In 1969,a GM Pontiac GTO "Judge" was road tested in the Nevada desert.
At 115-mph,the car,without the rear spoiler,generated 105-lbs front lift,and 250-lbs rear lift.
Those testing the car felt that due to the car's weight,none of this lift was an issue for stability.

The prevailing thinking of those times in America also suggested that larger/heavier cars cornered better because the weight kept them planted on the road. This classic thinking is alive and well even today, but that don't make it right - not in the slightest.

Just about everything I've done to my pick-up truck has been to get more down-force without sacrificing mpg's, and that has been my choice.

Anyone thinking it's safe to go 115 mph in a 2-ton muscle car has brass balls and perhaps got a hold of some good recreational drugs in 1969.

I'd do 110 mph on a motorcycle, or 140 mph in an old Porsche 911 before I'd do 115 mph in a 1969 GTO.

A friend of mine had a 1969 GTO back in 1979, pretty thrilling doing 60 mph on a side street, that thrill would soon turn to terror at truly high speeds I'm afraid.

115 mph at driver's discretion to say the very least.