Numerical simulations of unsteady flow field and non-uniform and non-equilibrium sediment transport in river bend

Subject Areas : Article frome a thesis

Mohsen Maghrebi ¹ , Seyyed Ali Akbar Salehi Neyshaboori ²

1 - Professor of Hydraulic Structure, Tarbiat Modares University
2 - School of Enviroment, College of Engineering, University of Tehran, Iran

Received: 2016-12-28 Accepted : 2020-07-11 Published : 2020-07-22

Keywords: Non-equilibrium sediment transport, CCHE2D numerical model, Flow field, River bend, Karon River,

Abstract :

Flow in river usually has a 3 dimensional character. While 3 dimensional flow simulations is time consuming process, enhanced 2D numerical modeling with depth and width averaged are introduced. In this article using field data, numerical simulation of unsteady flow field and non-uniform and non-equilibrium sediment transport in one reach of Karon River with length of 5.2 km for duration more than 6 years is performed using CCHE2D numerical model. Numerical outputs clearly demonstrate that CCHE2D numerical model can predict flow field in the study area. also the flow field analysis clearly demonstrate that high shear stress and high velocity has different zonal location and sediment transport analysis shows that van Raijn (1984) formula for adaptation length for bed load and Wee (1999) formula for adaptation factor for suspended load can better predict the bed change in the study area with good accuracy. Moreover the software accuracy for bed change varies between 11.045% to 68.07% in the study area.

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