Author(s): Mohammad Sedghi-Asl; Hassan Rahimi
Keywords: Friction factor; Manning's equation; non-Darcy flow; porous media; rockfill materials
Abstract: In this paper, the concept of Darcy–Weisbach's friction loss in pipe flows is employed and combined with Manning's widely used formula in open-channel flow problems to obtain a new relation for flow in porous rockfill media. A new formula to determine Manning's roughness coefficient of rockfill materials is presented based on the flow and grain characteristics and validated using new experimental data. The results confirm the applicability of Manning's formula for the hydraulically rough regime.