Numerical Investigation of the Inland Transport Impact on the Bed Erosion and Transport of Suspended Sediment: Propulsive System and Confinement Effect

• Main Authors: Sami Kaidi, Hassan Smaoui, Philippe Sergent
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Journal of Marine Science and Engineering
• Subjects: waterway sediment transport; CFD verification and validation; sediment scaling; ship hydrodynamics; propeller jet flow
• Online Access: https://www.mdpi.com/2077-1312/9/7/746

For competitive reasons, inland ships as maritime ships are increasingly larger with powerful propulsive systems. The impact of this evolution on the environment is multiple. One of the major impacts is the erosion of the channel bed and the sediment suspension. This erosion phenomenon is essentially caused by the turbulent flow around the ship generated by its movement as well as its propulsive system. Hence, for a better prediction and understanding of this phenomenon, it is indispensable to simulate with great precision the flow around the ship hull and the induced shear stress at the bottom. Different ways were used in the past to estimate the shear stress at the waterway bottom. Some of these ways are empirical, analytical and numerical using shallow water models. In the present work to study the erosion phenomenon caused by the inland transport, a sedimentary transport model was developed and implemented in the Computational Fluid Dynamics (CFD) model (Fluent) as external code. The coupled model was firstly verified and validated using measurements. The validated model was subsequently used to assess the influence of several parameters: depth (<i>h</i>) to draught (<i>T</i>) ratio, ship advance ratio (<i>J</i>), ship speed and sediment size (<i>d</i>₅₀). The first results show clearly that the coupled model behaves correctly and gives very satisfactory results. The impact of each parameter was compared and analyzed.