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Artigues-près-Bordeaux, France

Weiss M.,Departement Laboratoire Of Bordeaux | Weiss M.,National School of Public Works | Chenia M.,Annaba University | Ture Savadkoohi A.,National School of Public Works | And 3 more authors.
Nonlinear Dynamics | Year: 2015

Vibratory energy exchanges between two coupled oscillators is studied: the main elasto-plastic oscillator is coupled to a nonlinear energy sink(NES) with nonsmooth potential. Both oscillators are under pre-stressing terms. Two different methods are implemented for tracing system behaviours: (i) the time-event-driven technique which builds exact solutions of governing equations of the system phase by phase and (ii) the multi-scale method which traces system behaviours at different scales of time. It detects invariant of the system at fast timescale and equilibrium/singular points at slow timescales. The pre-stressing terms produce a more complex shape for the invariant, while detected dynamics at slow timescale let us have control at the behaviour of the system during its quasi-steady-state regime(s) which leads to have analytical design tools for tuning parameters of nonlinear energy sink according to design purposes (passive control and/or energy harvesting). © 2015 Springer Science+Business Media Dordrecht

Henine H.,IRSTEA | Henine H.,CNRS Transfers and Interactions in Hydrosystems and Soils | Nedelec Y.,Departement Laboratoire Of Bordeaux | Ribstein P.,CNRS Transfers and Interactions in Hydrosystems and Soils
Journal of Hydrology | Year: 2014

The effect of subsurface drainage on agricultural catchment outflow has been debated for quite some time. Concerning downstream peak flow, it is a complex task to predict the impact of agricultural drainage because different flow media are involved: the soil, pipe drainage networks and open channel networks. In France, drain pipes are designed to operate under a free-surface flow condition. Nevertheless, during intense rainfall events, some pipe sections may flow under pressurised conditions, so that a complex interaction between pipe networks and groundwater flows appears in the vicinity of these sections. In this paper, an integrated modelling strategy is considered in order to analyse these flow interactions. A 1D Saint-Venant network model is combined with a 2D Boussinesq shallow groundwater flow model by means of special internal boundary conditions which take into account the flow interactions. This study follows field experiments conducted in a small subsurface drained catchment, where drainage discharge and pressure heads were monitored in a buried pipe collector and water table profiles were monitored in the field. The simulation results of the coupled model are in good agreement with experimental observations. Moreover, it satisfactorily simulates the behaviour of the drainage system during the pressurisation stages. The model is also applied to a scenario addressing the effect of pressurisation, as compared to non-pressurisation, at the outlet. The coupled model reveals the relation existing between pipe pressurisation and hydrograph timing. Pipe pressurisation results in temporary storage of discharging water, which is released later when pressurisation stops. © 2014.

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