2004 Friction factors for smooth pipe flow

Friction factor data from two recent pipe flow experiments are combined to provide a comprehensive picture of the friction factor variation for Reynolds numbers from 10 to 36,000,000. For pipe flow, as long as entrance effects, roughness, and temperature variations are small, dimensional analysis indicates that the friction factor λ is only a function of the Reynolds number Re. That is, λ = f (Re) where λ = −(dP/dx)D