HYDRODYNAMIC BEHAVIOR OF COMPOUND RECTANGULAR OPEN CHANNELS

The hydrodynamic response of the turbulent flow in a compound rectangular open channel to the flood-plain depth, roughness, and symmetry, and to the channel Reynolds number is demonstrated. The flow in the four basic asymmetric channels measured by Tominaga and Nezu in 1991 is numerically simulated, as well as other channel configurations, including symmetric channels. Turbulence is modeled by the energy-dissipation model, combined with the algebraic stress model suggested by Naot and Rodi in 1982. The three-dimensional flow is solved using the parabolic pressure correction algorithm of Patankar and Spalding. The examples suggest estimations for the friction factors, and the mass exchange rate between the flood plain interior and its threshold.