Drag Force on Rigid Cylinder Formula

Equation for calculate drag force on rigid cylinder is,

$F=\frac{\mathrm{2·\pi ·\mu ·l·u}}{\mathrm{ln(l÷a)}}$

where,
μ = Dynamic viscosity of the fluid
l = Long length of the cylinder
u = Velosity of the moving cylinder
a = Radius of the base of the cylinder
π = pi (3.14159265358979)
F = Drag force on the rigid cylinder