Hydraulic Roughness of Corrugated Pipes

Original data on friction losses in two types of corrugated-metal pipes, obtained in the course of investigations into the hydraulic behavior of corrugated-metal culverts, are reported. A comprehensive friction factor-Reynold's number diagram, incorporating all published data on corrugated-metal pipes, is presented and used to develop a relationship between peak friction factors and relative depth of corrugations. A flow formula is developed to replace the Manning formula, but a table of n values, for use with the Manning formula, is also given.