Simulation 3D des ondes de batillage générées par le passage des bateaux et des processus associée de transport de sédiments

Les ondes de batillage générées par l avancement des bateaux détruisent les rives des voies navigables et accélèrent les phénomènes d érosion aussi bien au niveau des berges qu au niveau du fond du canal. Leurs caractéristiques cinématiques dépendent de la vitesse, de l enfoncement, du chargement du bateau et également de la profondeur de la voie navigable. En outre, les masses d eau accélérées par l immersion des bateaux et par leur système propulsif, induisent la remise en suspension d une grande quantité de sédiments et provoquent l érosion du fond de la voie navigable.Dans cette thèse, un modèle numérique 3D est présenté pour simuler la génération de ces ondes de batillage. Ce modèle, basé sur les équations de Navier-Stokes (RANS), a été couplé à un modèle d advection-diffusion 3D pour caractériser la répartition et le mode de transport sédimentaire au passage du bateau. Ce couplage est mis en oeuvre avec prise en compte des effets des hélices du système propulsif du bateau.Ship-generated waves in restricted waterways lead to the stream banks erosion and cause environmental damage which harms fish, plants, benthos, plankton, etc. They also alter the channel morphology because of the resuspension and transport of bed material by accelerated flows caused by moving-ships. The magnitude of these waves depends mainly on the geometrical and kinematical parameters of the convoy.The objective of this study is to predict the relationship between these geometrical and kinematical parameters and the amplitude of ship-generated waves as well as the water plane drawdown. Numerical simulations are conducted by solving the 3-dimensional Navier-Stokes equations along with the k- model for turbulent processes. The results are compared firstly with the empirical models and secondly with experimental measurements performed by the French Compagnie Nationale of Rhône (CNR). The exitance of the propeller increases the sediment in suspension. Therefore, the relationships between the re-suspended sediments and the advancing speeds of the convoy, the wakes generated by the moving convoy, as well as the number of barges are studied by adding 3D advection-diffusion equation and a propeller model.COMPIEGNE-BU (601592101) / SudocSudocFranceF

Simulation 3D des ondes de batillage générées par le passage des bateaux et des processus associée de transport de sédiments

Ship-generated waves in restricted waterways lead to the stream banks erosion and cause environmental damage which harms fish, plants, benthos, plankton, etc. They also alter the channel morphology because of the resuspension and transport of bed material by accelerated flows caused by moving-ships. The magnitude of these waves depends mainly on the geometrical and kinematical parameters of the convoy.The objective of this study is to predict the relationship between these geometrical and kinematical parameters and the amplitude of ship-generated waves as well as the water plane drawdown. Numerical simulations are conducted by solving the 3-dimensional Navier-Stokes equations along with the k-ε model for turbulent processes. The results are compared firstly with the empirical models and secondly with experimental measurements performed by the French Compagnie Nationale of Rhône (CNR). The exitance of the propeller increases the sediment in suspension. Therefore, the relationships between the re-suspended sediments and the advancing speeds of the convoy, the wakes generated by the moving convoy, as well as the number of barges are studied by adding 3D advection-diffusion equation and a propeller model.Les ondes de batillage générées par l’avancement des bateaux détruisent les rives des voies navigables et accélèrent les phénomènes d’érosion aussi bien au niveau des berges qu’au niveau du fond du canal. Leurs caractéristiques cinématiques dépendent de la vitesse, de l’enfoncement, du chargement du bateau et également de la profondeur de la voie navigable. En outre, les masses d’eau accélérées par l’immersion des bateaux et par leur système propulsif, induisent la remise en suspension d’une grande quantité de sédiments et provoquent l’érosion du fond de la voie navigable.Dans cette thèse, un modèle numérique 3D est présenté pour simuler la génération de ces ondes de batillage. Ce modèle, basé sur les équations de Navier-Stokes (RANS), a été couplé à un modèle d’advection-diffusion 3D pour caractériser la répartition et le mode de transport sédimentaire au passage du bateau. Ce couplage est mis en oeuvre avec prise en compte des effets des hélices du système propulsif du bateau

3D numerical modelling of shipwaves and associated sediment transport

Les ondes de batillage générées par l’avancement des bateaux détruisent les rives des voies navigables et accélèrent les phénomènes d’érosion aussi bien au niveau des berges qu’au niveau du fond du canal. Leurs caractéristiques cinématiques dépendent de la vitesse, de l’enfoncement, du chargement du bateau et également de la profondeur de la voie navigable. En outre, les masses d’eau accélérées par l’immersion des bateaux et par leur système propulsif, induisent la remise en suspension d’une grande quantité de sédiments et provoquent l’érosion du fond de la voie navigable.Dans cette thèse, un modèle numérique 3D est présenté pour simuler la génération de ces ondes de batillage. Ce modèle, basé sur les équations de Navier-Stokes (RANS), a été couplé à un modèle d’advection-diffusion 3D pour caractériser la répartition et le mode de transport sédimentaire au passage du bateau. Ce couplage est mis en oeuvre avec prise en compte des effets des hélices du système propulsif du bateau.Ship-generated waves in restricted waterways lead to the stream banks erosion and cause environmental damage which harms fish, plants, benthos, plankton, etc. They also alter the channel morphology because of the resuspension and transport of bed material by accelerated flows caused by moving-ships. The magnitude of these waves depends mainly on the geometrical and kinematical parameters of the convoy.The objective of this study is to predict the relationship between these geometrical and kinematical parameters and the amplitude of ship-generated waves as well as the water plane drawdown. Numerical simulations are conducted by solving the 3-dimensional Navier-Stokes equations along with the k-ε model for turbulent processes. The results are compared firstly with the empirical models and secondly with experimental measurements performed by the French Compagnie Nationale of Rhône (CNR). The exitance of the propeller increases the sediment in suspension. Therefore, the relationships between the re-suspended sediments and the advancing speeds of the convoy, the wakes generated by the moving convoy, as well as the number of barges are studied by adding 3D advection-diffusion equation and a propeller model

3D numerical simulation of ship-induced waves and sediment transport in restricted waterways

In inland waterways, the wave wake is the main factor that erodes the banks and the alluvial bottom. It may cause sediment resuspension into the water column. A 3D hydrodynamic model based on the Navier-Stokes equations is developed to reproduce these wave wakes and analyze their kinematic characteristics. Then, a 3D model of sediment transport is coupled with the hydrodynamic model to estimate the influence of the wakes and return current to the resuspension of sediments. The coupled model was validated with the experimental data of the Compagnie Nationale du Rhône (CNR, 1997b). The numerical results show that the maximum value of Suspended Particulate Matter (SPM) is proportional to the Froude number (Fr), and also used to estimate the influence of the blocking coefficient (Cb) on sediment transport induced by the passing ship

Transonic flutter analysis of an AGARD 445.6 wing in the frequency domain using the Euler method

A method based on the Euler equations is proposed for solving transonic flutter problems. The transonic nonlinear flow field with local shock wave/boundary layer interaction is obtained by the Euler/boundary layer equations, and the aerodynamic forces are converted from the time domain to the frequency domain using system identification techniques. The structural dynamic equations in generalized coordinates are adopted for solving structure problems. The method is validated by a flutter boundary prediction of the AGARD 445.6 wing model. The simulation results show that the method presented in this paper is accurate for the prediction of transonic flutter boundary through comparison with experimental data and other simulation results. Furthermore, the present frequency domain method is also much more efficient than the time domain method

MEMS Device for Quantitative In Situ Mechanical Testing in Electron Microscope

In this work, we designed a micro-electromechanical systems (MEMS) device that allows simultaneous direct measurement of mechanical properties during deformation under external stress and characterization of the evolution of nanomaterial microstructure within a transmission electron microscope. This MEMS device makes it easy to establish the correlation between microstructure and mechanical properties of nanomaterials. The device uses piezoresistive sensors to measure the force and displacement of nanomaterials qualitatively, e.g., in wire and thin plate forms. The device has a theoretical displacement resolution of 0.19 nm and a force resolution of 2.1 μN. The device has a theoretical displacement range limit of 5.47 μm and a load range limit of 55.0 mN