Study effect of flow hydraulic conditions on the secondary flow pattern in bend meanders using SSIIM mathematical model

Natural rivers are one of the main sources of water and energy. Design and management of natural rivers needs a complete understanding of mechanics of flow pattern and sediment transport. The complex three-dimensional flow characteristics in river bends necessitates the use of a three-dimensional numerical model. The purpose of this study is predict the flow pattern and location of erosion and depositional in Sine-Generated channels, Also, the effect of Froude number and the ratio of width to depth on flow and bed shear stress considered.
The numerical model used in the present study is called SSIIM, an acronym for sediment simulation in intakes with multi block option. In this study is predict the flow pattern and location of erosion and depositional in Sine-Generated channel having 50 0 with rigid bed. The k and SST k models were used to predict the turbulence in this simulation. For verification of the results of the numerical model the experimental data (da Silva and Tape) was used.
By changing the Froude number from 0.15 to 0.41, flow pattern and velocity distribution did not change but increased erosion. Also by decrease width to depth ratio form 12.5 to 4 the number of rotary cells in Section increased from 2 to 3 number and it was found in wider rivers, power of secondary flow decrease but the downside and the upside of it is the same deep rives.
The result of simulation shows that SST kmodel has better accordance with experimental data than kmodel. Distribution of bed shear stress depends on Froude number although secondary flow is independent. Furthermore, distribution of bed shear stress and secondary flow is dependent on the width to depth ratio, so that the for b/h