Design of a didactic activity based on the Hazen-Williams model for engineering education

International audience ; The research presented is focused on engineering education, framed in the Anthropological Theory of Didactics (ATD), whose objective is to design a didactic activity of mathematical modelling. For this purpose, didactic engineering is considered. The starting point is the analysis of a civil engineers' workplace. A praxeology based on the Hazen-Williams model to design pipelines is identified using notions of hydraulics, topography, and mathematics. A didactic transposition on this praxeology is performed. A mathematical modelling activity is designed and implemented with students in the fluid mechanics' course. The central task is to determine the diameter of the pipe and ensure a water flow rate of 50lts/s. The handling of the mathematical model requires a qualitative analysis of the variables at stake and to relate knowledge of various kinds.