mayf-
The new (since 1997) C5 Corvette has the 2nd lowest Cd of any regular production
car, Cd = 0.287 for the targa coupe (0.31 for the hardtop, and 0.32 for the
convertible). The frontal area for all three is 21.42 sq. feet (1.99 sq meters).
This is well publicized in the Corvette world, all the sales brochures, auto
magazines like Motor Trend (Feb 97 page 43), etc. The General Motors EV-1
(Electric Vehicle) has the lowest drag of any production car in the world, 0.21
Cd. Several thousand have been leased in 5 major metropolitan areas for the past
2 years.
Check out Bruce Bowling's web site http://sura1.jlab.org/~grippo/auto.html.
Scroll down in the top box to "Aerodynamic and Rolling HP Computator". I don't
exactly understand which coefficient relates to the presumably asphalt /
concrete coefficient of friction in the equation. I'd like to know how to modify
the coefficient for the salt.
I have built a fairly involved Excel spreadsheet to model a car to determine
accurately the HP required to get to a given speed (C/GT and C/BGT is my class).
I used Bruce Bowling's equations plus textbook aerodynamic calculatons to arrive
at a model that seems to be pretty accurate. Now I need to understand salt
friction better, but can't find any way to contact this guy Bruce Bowling.
--- Ron, USFRA
"Lawrence E. & Cathy R. Mayfield" <lemay@hiwaay.net> on 12/17/99 02:25:55 AM
Please respond to "Lawrence E. & Cathy R. Mayfield" <lemay@hiwaay.net>
To: land-speed@autox.team.net
cc: (bcc: Ronald B Anderson)
Subject: Drag Coefficients and Frontal Area
Keith asked the other day aboout the smallest, narrowest, longest available
vehicles. Been thinking about that: what we need is the automobile with the
lowest drag available and this would be found from the drag coefficient
times the frontal area. This would always be constant no matter where we race.
So here's the challenge. Over the next two weeks or so, how about the
members of the list that can surf the web, look for sites that have actual
data on Cd and frontal area. If any member has a reference book that he/she
would share the data from, it would be appreciated. If I can get the data,
I will compile a list of vehicle frontal areas, Cd and a computed drag
factor (Cd x Area). I'll include the formula for drag so everyone
interested can determine their own set of numbers for whatever speed they
desire.
Send data to me!
mayf
L.E. Mayfield
124 Maximillion Drive
Madison, Al. 35758-8171
1-256-837-1051
old >>>>>>>> http://www.hsv.tis.net/~mayfield
new >>>>>>>> http://home.hiwaay.net/~lemayf
DrMayf@AOL.com
lemay@hiwaay.net <<<<preferred
Sunbeam Tiger, B9471136
Sunbeam Alpine Bonneville Land Speed Racer,
'66 Hydroplane Drag Boat (390 FE)
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