A Numerical Study of the Effects of Roughness, Pattern, Height and the Shape of roughness on Controlling Turbidity Currents using ANSYS-CFX

Abstract

Turbidity currents are one of the most fundamental contributors to the transfer of sediments near dams. In this article, the effect of the roughness, pattern, height and shape of the sediments on the bed in controlling turbidity currents were studied using theFinite Element Method through ANSYS-CFX .The K-ε method was used to compute turbulence . After model calibration, flow without roughness was simulated. Afterwards, three shapes of roughness, namely pyramid-shaped, round-edged cylindrical and cubic roughnesses, were modeled with zigzag and consecutive formations, in 5 different roughness heights in subcritical and supercritical flow regimes. The results indicated that with the increase in the height of the roughnesses and cross flow against the current and with the creation of a zigzag arrangement, there was a decrease in turbidity current discharge. Also, the controlling effect of roughness on turbidity currents was more in the subcritical flow.