Analogy between developing laminar flows in curved pipes and orthogonally rotating pipes

This paper describes a quantitative analogy between developing laminar flow s in the inlet regions of curved pipes and orthogonally rotating straight p ipes through similarity arguments and computational studies, Three-dimensio nal developments of these flows are characterized by secondary flows due to the centrifugal or the Coriolis force. Similarity considerations with taki ng the secondary flow into account result in a pair of governing parameters and a dimensionless axial distance for each flow. When the second paramete r is large enough in each flow, we have a quantitative analogy between them : the computed results for the two flows show strong similarity regarding t he developments of flow structure, wall friction, and velocity profile of p rimary and secondary flows.