Drag Coefficient

A dimensionless value that allows the comparison of shape and orientation of different bodies.

The force on an object due to aerodynamic drag can be calculated using:

F = aerodynamic drag force [N]
Cd = drag coefficient
A = frontal area [m2]
ρ = density of fluid [kgm-3]
v = velocity of object relative to fluid [ms-1]
Re = Reynolds number

Circular flat plate
Cd = 1.12
Re ~ 1e6
A = πd2/4
Cd = 0.45
Re < 2e5
A = πd2/4

Cd = 0.2
Re > 2e5
A = πd2/4
Solid Hemisphere
Cd = 0.38
Re = 1e3
A = πd2/4
Solid Hemisphere
Cd = 1.17
Re = 1e3
A = πd2/4
Miscellaneous Objects
1.0 to 1.4skydiver
1.0 to 1.3person standing
0.7 to 1.1formula one race car
0.6bicycle with faring
0.35 to 0.45light truck
0.25 to 0.35car
0.15airfoil at stall

See also: Drag, Frontal Area, Pressure Coefficient, Reynolds Number, Vehicle Aerodynamic Drag.

Previous PageView links to and from this pageNext Page

Subjects: Aerodynamics Fluid Dynamics

Aerospaceweb.org - Golf Ball Dimples The aerodynamics of spheres and spheres with dimples - more commonly known as golf balls.