Related Resources: fluid flow

Circular Flat Disk Drag Coefficient and Drag Equation

Air Flow Drag, Drag Coefficient Equation and Calculators
Fluids Design and Engineering Data

Air Flow Drag and Drag Coefficient Equations and Calculator

The drag coefficient (non-dimensional drag) is equal to the drag force divided by the product of velocity pressure and frontal area. The velocity may be that of the object through the air (or any other gas) or the air velocity past a stationary object. Coefficients are given for a number of geometrical shapes and also for cars, airships and struts.

Drag Equation:

Illustration	Description	L / d	Cd	Re / 104	Frontal Area
	Circular Flat Disk Drag	-	1.12	100	π d2 / 4

Where:

D = Drag (N);
C_d = Drag Coefficient (unit less);
ρ = fluid density (kg/m³);
A =frontal area (m²);
V = fluid velocity (m/sec);
d = Diameter (m);
R_e = Reynolds Number (unit less)

Density of air = 1.225 kg/m³