Time-Varying Bottom Friction due to Waves and Current Interacting at An Arbitrary Angle

Abstract

A simple method is proposed to calculate an instantaneous bottom shear stress under waves and current crossing at an arbitrary angle, on the basis of the theoretical study of Tanaka and Shuto (1981). Although the exact solution derived Tanaka and Shuto is expressed in terms of the complex-valued Bessel functions, the approximate solution presented in this study is very simple with reasonable accuracy. This method can, therefore, be extensively applied to practical coastal problems such as sediment transport and wave energy attenuation under coexistence of waves and current.

Computational Mechanics of Vertical Sorting of Sediment in Sheetflow Regime by 3D Granular Material Model

“…Small, middle and large three classes of plastic particles are mixed in a ratio shown in Particles are mixed sufficiently so that each class of particle exists in equal ratio. The oscillatory flow was T=5.0 s in period, U max =85.0 cm/s in flow-velocity amplitude at the center of cross section, and Y=0.27 in Shields number for mean diameter, in which frictional coefficient is estimated following Tanaka and Thu[1994]. The hydraulic condition of this experiment corresponds to the in the sheetflow regime as indicated by the previous study of Asano [1995].…”