Keqi Zheng

Equivalent Roughness Height for Nondensely Distributed Submerged Obstacles in Open Channel Flows

Abstract The estimation of equivalent sand-grain roughness height ( k s ) for open channel flows is well-established for densely packed roughness but remains ambiguous for nondensely distributed submerged obstacles. This study presents a practical model to predict k s for such co...

Unified Friction Factor Model for Dune Beds from High to Low Submergence

Abstract Accurate prediction of flow resistance in dune-bed streams is critical for river engineering and flood management. Traditional methods, which rely on empirically partitioning total shear stress into skin and form drag, often fail under low-submergence conditions where th...