Drag coefficient cd examples (Courtesy of Wikipedia)

Drag coefficient c_d examples

[edit]General

In general,  is not an absolute constant for a given body shape. It varies with the speed of airflow (or more generally with Reynolds number ). A smooth sphere, for example, has a  that varies from high values for laminar flow to 0.47 for turbulent flow.http://en.wikipedia.org/wiki/Drag_coefficient

Shapes

cd	Item
0.001	laminar flat plate parallel to the flow ()
0.005	turbulent flat plate parallel to the flow ()
0.075	Pac-car
0.1	smooth sphere ()
0.186	Schlörwagen 1939 [13]
0.19	General Motors EV1 1996[14]
0.24	Tesla Model S 2012[15] Mercedes-Benz E-Class Coupé 2010[16] best production cars
0.25	3rd Generation Toyota Prius
0.295	bullet (not ogive, at subsonic velocity)
0.48	rough sphere (), Volkswagen Beetle[17][18]
0.7	a typical bicycle plus cyclist[citation needed]
0.75	a typical model rocket[19]
.8-.9	coffee filter, face-up
1.0–1.1	skier
1.0–1.3	wires and cables
1.0–1.3	man (upright position)
1.1-1.3	ski jumper[20]
1.28	flat plate perpendicular to flow (3D)
1.3–1.5	Empire State Building
1.8–2.0	Eiffel Tower
1.98–2.05	flat plate perpendicular to flow (2D)
2.1	a smooth brick[citation needed]