Aerodynamics Seminar # 4 - by Phil Knox

[MetroMPG]

This post was originally written by Phil Knox (aerohead), and it first appeared on the MaxMPG group. Phil has done a lot of work educating the masses about the critical role aerodynamics play in efficiency, and has spurred many in the DIY crowd to take matters into their own hands.

This is the fourth in a series which I'm reproducing here with permission.

Go to: Aerodynamics Seminar Index

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Aerodynamics Seminar # 4 - by Phil Knox

Hey everyone,as I mentioned in the last installment, I wanted to pay homage to the giants for whom we stand on their shoulders. As I'm still educating myself,I'm gonna miss some,however its a start.

Since aerodynamics is a branch of fluid dynamics, I need to mention some of these pioneers, however I need to do a little homework first. Since John Gilkison mentioned a few air heads,we'll jump in there.

The theme here is that alot of serious investigators have dedicated their lives to pushing the state of the art in aero knowledge. Their work is recorded for us and represents a vast body of untapped potential.

Everything revolves around physics, and physics is way underrated, it's fun and not just for geeks. All the top people in speed records etc.,have worked with physics not against it,to break into new territory. Sir Issac Newton's work is alive in aerodynamics. Otto Lilianthal, Octave Chanute, Gustav Eiffel,the Wright Bros., Charles Lindbergh, Chuck Yeager,etc.,all scored victories in their endeavors by respecting physics and the limitations and also opportunities that it presents.

Lilianthal inferred the efficiency of bird bodies in his research. Eiffel's "ice cream cone" form is uncanny in its resemblence to a birds body. Gauledet's record- setting "bullet"aircraft of 1913 was almost a clone of Eiffel's cone. Working at the Zeppelin Werk on Lake Constance,Paul Jaray and Klemperer would refine the ice cream cone into the Cd0.05 airship as the famous HINDENBURGH.

While in between airship studies,Jaray turned his attention to automobiles and in the 1920s had basically nailed the low-drag auto form,which lives in recent times in Solar Cars,Bonneville land speed record cars,Mercedes mileage record cars, Volkswagen record mileage cars,the Oldsmobile Aerotech closed- course speed champion.

There were even production cars which borrowed from Jaray.The German Adler of 1937 and Czechoslovakian TATRA,also of 1937,both shared the Jaray body theme. Dr.Ferdinand Porshe' first sports car borrowed heavily from Jaray. Jaray would have been proud of R.Buckminster Fuller's Dymaxion Car of 1934. Designer Larry Shinoda of General Motors almost succeeded in bringing a Jaray Corvair Monza to life in the 1960s. Preston Tuckers Tucker Torpedo of 1948 had many Jaray elements.

In the 1960s, Kamm-back cars were offered as performance cars. Kamm-back is a media *******ization just as flying-saucer. When Kenneth Arnold reported a UFO over Washington State,he described its peculiar flight characteristics as that of a saucer skipping over water. It was a U.P. journalist who coined the term flying saucer not Arnold.

In the same vein,Kamm's work involved the front of the car not the back. Kamm took air from the engine bay and released it at the base of the windshield where it energized the flow which otherwise would be stalling. By doing so,the air stayed attached over the roof,all the way to the rear of the car,cutting drag. Kamm observed that since the flow was attached over the entire length of the roof, stylists would have lattitude in where they ended the roof without affecting the flow, such that they could chop off the roof wherever they wanted.

In his K-Car, Kamm's roof follows the architecture of Jaray,with gentle reduction in cross-sectional area as the roofline projects to the rear.Just like a boattail!

Times up gotta go. Til next time, Phil.