[H-GM01] Geomorphology

[HGM01-05] Velocity and Sediment Concentratin Distributions of Turbidity Currents

*Sytharith Pen¹, Norihiro Izumi¹ (1.Hokkaido University)

Keywords:turbidity current

Abstract. In this work, we present a mathematical model to describe the
distribution of the velocity and the particle concentration of the turbidity
currents. The turbidity current is described by the Navier-Stokes equations
with the use of Boussinesq approximation to approximate the e ect of sed-
iment concentration on the
ow, the di usion/dispersion equation for the
sediment transport, and k- turbulence model for the problem closure. The
model is simpli ed by a roof-like con guration which allows a steady equilib-
rium state of the
ow. The numerical solution of the distribution of the
ow
velocity, the sediment concentration, the turbulence energy, and the dissipa-
tion rate are obtained by the nite-di erent numerical scheme. The study
shows that the entrainment capacity of sediment due to turbulence and the
dampening characteristic of turbulence is aliated with Richarson number
and non-dimensional settling velocity. The model is capable of capturing the
fundamental characteristics of the turbidity current which provides a vital
base state for the analysis of morphodynamics generated by the turbidity
current.