Pressure thrust?
 

Check this out. Could be of major import, but certainly provocative:

Pressure Thrust

Theory holds that in aft body, pressure recovery can be used to provide negative drag, or thrust. NASA per Goldschmied and Bushnell have worked on this, with potential for major fuel savings.

Please do a little Googling with keywords "pressure thrust," "David Birkenstock," "Goldschmied," read what they have to say, and discuss here.

an interesting idea... i've always wondered it it was possible to design a sort of "wing"in the broad sense of the word, that in stead of generating lift at the top would generate pressure at the end... there would naturally be a loss of energy, but if this shape could be roughly car like than you'd have a car that in stead of having drag at the end would have pressure at the end.

a quick google search generated this image

http://i77.photobucket.com/albums/j5...p_64_color.jpg

wich reminded me of something else... this:

http://i77.photobucket.com/albums/j5...st/above-z.jpg

i admid a rather loose association, but still....

Hi All,

Does the figure in the OP's link remind anybody of a Saab 900 ?

What about the direction of the pressure?

now you mention it, however the saab 900 actually wasn't so aero as veryone wants to believe it's cd was around 0.40 if i remember correctly... the big whale spoiler helped a lot to improve that though.

a rather square body with this saab like rear angle is know as a morell body, i don't have much info on it, but basically the sides act like two vortex generators wich produce two large counter rotating vortices... this is quite bad for aero.

this body style was quite comming in the 70's and 80's and you frequently see these cars have spoilers installed below the windshield to reduce the size of the vortex... usually the Cd numbers of car with and without the spoiler are vastly appart .

Who remembers that car as aerodynamic? It's like a Cherokee, but with a sloped back.. Actually the windshield is more vertical than a Cherokee's
http://www.saabhistory.com/blog/wp-c...ladega_600.jpg

Here's a link to aircraft design: Pressure Thrust- The Future of Aviation? | Airliners.net
It features the cad drawing as per an earlier post but also some interesting reading on it's use on aircraft. Could the efficiency figures quoted be any way close? If so then this concept needs to go mainstream NOW!

ollie

My grandpa once told me that a properly-designed full engine cowling on a radial-engined airplane actually pulled the airplane forward a bit. Sounds like the same sort of idea.

(Boy do I miss him!)

-soD

Looks like a bullet. Which, consequently, is about the same shape as a missile or an older bomb. And now you know where the technology will rear it's head first. ;)

Several Bonneville salt flats racers have toyed with the idea of racing a Posche 928 in one of the factory production classes...

but running it with the body on backward!