NONUNIFORM LAMINAR FREE-SURFACE FLOW.

A one-dimensional analysis is undertaken of laminar flow in horizontal open channels of rectangular cross-section. A closed-form analytical solution is obtained for the non-dimensional surface profiles. The non-dimensional profiles are independent of the Reynolds number of flow but are a distinct function of the aspect ratio of the flow cross section. The analytically predicted profiles are found to be in good agreement with the results of experimental observations, except in the immediate vicinity of the critical depth where small discrepancies occur.