Patterns of flow in meandering channels of varying sinuosity

The flow patterns of rough turbulent, steady, meandering flows of varying sinuosity are investigated experimentally. In agreement with the behaviour of large-scale natural alluvial streams, it is assumed that the width-to-depth ratio is large; the channel centreline is a sine-generated curve, the banks are rigid, the channel cross-section is rectangular. In contrast to previous theoretical works, where the computed flow patterns were of the same character, irrespective of the sinuosity of the channel, it is found that every different plan geometry of a meandering flow has its own flow pattern. The deviation angle between the vertically-averaged streamlines and the coordinate lines is used to formulate the variation of flow pattern with sinuosity.