SPATIAL LINEAR STABILITY ANALYSIS OF OPEN-CHANNEL FLOWS WITH TRANSVERSE SHEAR REVISITED

Abstract

 Based upon the shallow water equations, linear stability analysis is conducted on an open-channel flow with velocity retardation on one side. The analysis is applied to a steady turbulent base flow which is characterized by a sub-depth scale turbulence derived from a logarithmic profile of vertical velocity. The linear stability analysis is performed for the case of spatially growing disturbances and compared to the case of temporally growing disturbances. We found that discrepancies between results from the spatial and the temporal approaches were less relevant when the bed friction effect and the kinematic eddy viscosity effect were more significant.