It is of significant importance for longshore current instability to nearshore hydrodynamic and sediment transport. To further study the mechanism of longshore current instability, this paper obtains different instability growth modes and its reasons caused by the different velocity profile characteristics of slope 1 : 100 and 1 : 40 based on the experimental study of longshore current instability by using the linear shear instability model. The results show that: (1) The instability of longshore current only exists backshear mode for slope 1 : 40 and may exist frontshear and backshear modes for slope 1 ':100. (2) The peaks of linear instability growth mode for slope 1 :100 correspond to three cases, the dominant peak is formed by thejoint action of frontshear and backshear or by backshear alone. The results of oscillation period, wavelength and spatial variation obtained by analysis of linear shear instability are agreed with the experimental results.
展开▼
