انجمن هیدرولیک ایران نشریه علمی هیدرولیک 2345-4237 4 2 2009 08 23 Numerical Simulation of Bed Evolution in 180 Degree Alluvial Channel Bend شبیه سازی عددی تغییرات بستر کانال های آبرفتی در قوس 180 درجه 35 43 85521 10.30482/jhyd.2009.85521 FA علی سواریان امیر حسین نیک سرشت دانشگاه صنعتی شیراز ناصر طالب بیدختی 0000-0002-9322-2416 Journal Article 2009 03 23 The river bed evolution in 180 degree alluvial channel bend is numerically simulated using FLUENT<br />based on Eulerian two-phase model that implements Euler–Euler coupled governing equations for<br />fluid and solid phases and a modified k–; turbulence closure for the fluid phase. This two-phase model<br />predicts sediment transport from more fundamental dynamical equations, thereby avoiding the use of<br />purely empirical sediment transport formula. Such formulas have been found to be case-dependent,<br />thus limiting their general use to cover a broad range of flow configurations. Both flow–particle and<br />particle–particle interactions are considered in the model. During the simulations, the interface<br />between sand and water is specified using a threshold volume fraction of sand, and the evolution of the<br />bed form is studied in detail. The predictions of bed form evolution are in good agreement with<br />previous laboratory measurements. In addition, the computational results indicate the presence of a<br />new mechanism in sediment transport that can be called 'Laminated Load' hereafter. https://jhyd.iha.ir/article_85521_c9311604a2221564bb09c9b89bdfc401.pdf