A Simpler Method of obtaining Adler’s Criterion for Flow in Curved Pipes

A simple and direct method based on magnitude considerations is presented in obtaining the Adler’s Criterion [ N_R (a/R)^1/2]^1/2 which relates the resistance of a curved pipe with that of a straight pipe when the flow is laminar at higher Reynold’s numbers. The same assumptions that were made by Adler are made in obtaining the criterion.