Author(s): Shu-Qing Yang

Linked Author(s): Shuqing Yang

Keywords: Unsteady flow; Shields number; Rouse number; Sediment transport; Vertical velocity;

Abstract: This paper introduces a formula of sediment transport (ST) that is applicable in rivers, estuaries and coastal waters. Different from previous ST formulae that include parameters in streamwise direction without parameters in vertical direction. Different from this assumption, this paper highlights the importance of vertical motion V and the vertical velocity is suggested to represent the vertical motion. A connection between ST and vertical velocity V is established. It is found that upward vertical velocity plays an important role for sediment transport, its temporal and spatial alternations are responsible for the phase lag phenomenon and bedform formation. Finally the mechanism of bedforms is extended to explain the formation of ocean waves. Different from existing research, the shear stress plays no role for waves, only the vertical motions dominate the ocean waves. Reasonable agreement between the measured and the proposed conceptual model was achieved.

DOI: https://doi.org/10.3850/38WC092019-0686

Year: 2019