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Accueil > Présentation > Projets > Hydralp

Overview

This project aims at the renovation and upgrade of two facilities dedicated to the laboratory modelling of environmental fluid motions : the multidirectional wave basin (LHF) at Sogreah, and the Coriolis platform at the Laboratoire des Ecoulement Géophysiques et Industriels (LEGI) , both located in the urban area of Grenoble. LEGI is jointly run by the Centre National de la Recherche Scientifique (CNRS), the Université Joseph Fourier (UJF) and the Institut Polytechnique de Grenoble (Grenoble-INP), which manages this project. The LHF basin is a joint venture of Grenoble-INP and the private consulting and engineering company Sogreah, which is 25% time available for academic research. This certainly makes the LHF a pioneer of the Equipex program.

The two other partners of the project are ETNA/Cemagref in Grenoble, and GAME/CNRM, jointly run by CNRS and Météo-France in Toulouse. They bring their expertise, respectively in granular flows and atmospheric dynamics, and open new fields of application for both facilities. ETNA/Cemagref will be in charge of a program on long-term dyke evolution under wave effects, in relation with flood control. On the Coriolis platform, it will be in charge of a circular channel configuration, simulating the long-term behavior of multi-size granular materials in river beds. GAME/CNRM will study atmospheric dynamics on the Coriolis platform, in relation with its own (non-rotating) channel for density stratified flows and its developments in numerical modeling.

The multidirectional wave basin of LHF, inaugurated in 1991, is widely used for the testing of coastal engineering equipment, as well as for fundamental studies of near-shore physics. The hydrodynamic phenomena associated with the transformation of waves and tides in coastal environments play a key role in the mixing of water masses, in sediment transport and the evolution of the coastline. Moreover, extreme waves and storm surges have shown their terrible destructiveness in recent years. The understanding and modelling of these phenomena is still a major scientific challenge, with major economic outcome in civil engineering.

The Coriolis platform was built in 1960 as a model of tidal currents in the English Channel, and further renovated in 1985 as a 13 m diameter rotating tank for fundamental studies in oceanic and atmospheric flows. It contributed to the development of a strong oceanographic team at Grenoble, and the expertise gained on tides was decisive for the development of oceanographic altimetry, contributing to operational oceanography and climate modelling. Through a succession of European and national projects it accompanied the progress in oceanography and atmospheric dynamics over the last 20 years. The Coriolis platform is a unique infrastructure in Europe, and even world-wide, and since 1992, it has been continuously supported by the European Commission through the programs ‘Access to Major Research Infrastructures’. Since 2006, international access is part of an ‘Integrated Infrastructure Initiative’ Hydralab III, involving close collaboration with wave basins and other major unique infrastructures in hydraulics. This initiative extends during 2010-2014 as Hydralab IV, which also includes the stratified flume at GAME/CNRM.

Thorough renovation is needed for both ageing facilities, and the asset and unique expertise would be lost in the absence of a new investment. For the multidirectional wave basin, a new 3D wave maker needs to be installed to reach modern standards in wave property control. Furthermore, the implementation of recent instrumentation (acoustical and optical) requires the conception of a new support and illumination system over the whole 30x30 m2 basin. The reconstruction of the Coriolis platform is part of the ‘plan campus’, a profound restructuration of the academic and research infrastructures in the Grenoble area. This program provides the funding for the new building. The new rotating platform will be improved in terms of speed, vibration control and logistics. It will provide new possibilities, in particular the circular channel configuration complementing the neighbouring equipments of ETNA/Cemagref. The closer contact with LEGI and laboratories on environment and geophysics will be also decisive in terms of scientific animation and logistic support.

The grouping of the two pieces of equipment into a single project will promote collaborative work on common instrumentation, as already developed within the joint participation to the European Initiative Hydralab. Moreover there are close scientific links, with common scientific issues in waves, turbulence and granular flows. This is why we suggest a unique scientific committee. It will contribute to the structuring of the Ecouflu program of Envirhonalp and is integrated in the Observatoire des Sciences de l’Univers de Grenoble (OSUG).

The proposed equipment will address many scientific issues, related to the basic understanding of wave breaking and turbulence, boundary layers with density stratification or complex topography, energy dissipation and mixing in the ocean, morpho-dynamics of the littoral and the deep ocean. Thanks to the large size of the facilities, multi-scale processes typical of natural phenomena will be accessible, yet under much better controlled conditions than most field studies. The difficulty of measurements and logistic constraints are often bottlenecks in large laboratory facilities for fluid mechanics. The proposed instrumentation system and practical design will provide efficient access and novel measurement capabilities, with technical and scientific support for external users of the equipment. Furthermore data base of results will be produced, in relation with OSUG, so that the heavy effort of data collection will be more widely exploited.

The equipment will be open to projects managed by external users, selected by a specific scientific committee or by the committee of the INSU program LEFE-IDAO or RELIEFS. International access will be sought within the ongoing European Integrated Infrastructure Initiative Hydralab IV and the project EUHIT (European High-Performance Infrastructures in Turbulence). It will be widely open to the private sector and societal needs, with the added value of the consulting activity of the company Sogreah.

The unified approach to environmental flow problems provided by this infrastructure is an excellent support for the academic education of the 21 st century. In the traditional views, students can be trained in meteorological forecast, oceanography, or civil engineering, with little overlap. However there is an increasing need to reliably assess the effect of global climatic change on various environmental problems, for risk assessment or investment planning. While the computing resources and computer codes become more widely available, the shift of the training will move to the physical understanding of the processed involved, rather than skills in applied mathematics and computer programming. Laboratory models are very effective for providing this training, and the large scale facilities are needed to address the relevant multi-scale phenomena.

A strong increase in the demand of physical modelling can be already observed during the last decade, after a phase of decline during the previous decade. The growth of the activity of Sogreah is deeply rooted in their expertise in physical modelling. We foresee that the renewed facilities, and the wider expertise and visibility provided by this project, will provide novel opportunities for economic developments.