Julián AguirreMaría Luisa OliveroR. Fuentes2026-03-222026-03-221986https://andeanlibrary.org/handle/123456789/64170Taking into account the wakes past the elements, a model has been developed in order to extend the logarithmic law to the calculation of friction factors in the case of large roughness flow in open channels. The model postulates a relationship between the thickness of the wake and the height of the roughness elements; this conjecture has been ckecked successfully through adequate experimental data. The relationship contains a coefficient s associated to the wakes. This coefficient has been measured for some regular shapes of roughness elements and also for some natural sediments.esSurface finishWakeConjectureGeometryLogarithmSurface roughnessGeologyMathematicsMechanicsPhysicsarticle