Effect of Coriolis force on the linear stability of subaqueous dunes with erodible and non-erodible beds

Dunes, are wavy-shaped structures, that can be found on river shores and underwater. We aim to investigate the influence of Coriolis effect on the linear stability of subaqueous dunes using a simple model based on the three-dimensional shallow water equations written in rotating frame of reference. The analysis is performed for both erodible and non-erodible beds. Our analytical results in the absence of Coriolis force are verified with published results. The wave speed and growth rate of disturbances are presented for different Coriolis parameter, Froude number and erodibility. A new mode is observed, which becomes unstable beyond a threshold value of Coriolis parameter. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study investigates the influence of the Coriolis effect on the linear stability of subaqueous dunes using a simple model based on the shallow water equations in a rotating frame of reference. New unstable modes are observed beyond a threshold value of the Coriolis parameter. Analytical results show variations in wave speed and growth rate of disturbances under different parameters, with the dunes becoming unstable when the Coriolis parameter exceeds a certain threshold.