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Histoire du musée
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Research projects
The various projects carried out at the LMFN revolve mainly around the research programs of the two professors in charge:
G. Dumas
Hydrokinetic Energy: Turbine technologies and Array Deployment Optimization through CFD
M. Olivier
Numerical simulation of fluid-structure interactions and multiphysics phenomena in fluid flows
Depending on requests for collaboration from university or government partners and private companies, additional projects are added on a regular basis.
Active projects
Développement d'une hydrolienne à ailes oscillantes avec mécanismes passifs ou semi-passifs.
Optimisation d'une turbine à axe-vertical par l'ajout de flexibilité (interactions fluide-structure).
Développement et validation d'une m éthode de représentation de turbines au sein d'un parc (méthode EPTM) par l'ajout de termes sources de haute fidélité à une région d'actuation.
Caractérisation des sillages pour diverses technologies de turbines.
Optimisation de la configuration de cylindres perpendiculaires pour l'obtention d'oscillations induites par vortex.
Optimisation des performances d'une turbine à axe vertical par l'ajout de plaques de bout détachées et de modifications au design des supports.
Développement d'algorithmes de couplage fluide-structure.
Active projects
Context
The rise of fuel prices together with the international commitments to limit global warming effects have motivated significant research efforts in recent years on alternative energy sources that are clean and renewable. Wind and solar energy are well known examples, to which one can now add the huge amount of kinetic energy available in river and tidal flows.
Hydroelectricity and hydrokinetic turbines
In the province of Quebec, 96% [1] of the electricity production comes from hydroelectricity.
The potential energy of water elevation in an artificial reservoir constitutes the basic energy source of hydroelectricity. Electricity is produced when the water flows through hydraulic turbines down the dam ducts.
Instead of building a dam on a river, it is possible to install turbine units converting the kinetic energy of flowing water to electricity in a manner very similar as wind turbines do in air. These turbines are named hydrokinetic turbines.
Hydrokinetic turbines may be installed in river or on the seabed to capture tidal energy and many units can be deployed and gathered in favorable sites, within farms of underwater turbines.
[1] Source : Hydro-Québec
Hydrokinetic vs wind turbines
The hydrokinetic turbines sector is growing fast with several new concepts and prototypes being developed in many countries. Nonetheless, the hydrokinetic technology is currently in its development stage comparable to where wind turbines were 30 years ago. However, this development is expected to be faster due to the favorable political and social contexts, and to the many technological advances realized since then (new composite materials, advanced numerical simulation tools, etc).
The purpose of a hydrokinetic turbine is to extract a fraction of the kinetic energy contained in a water current in much the same way as one does with air using a wind turbine. However, to extract energy from river and tidal flows rather than from the wind offers significant advantages, among which:
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a greater energy density — at equal rated power, a hydrokinetic turbine will have an area 20 times smaller than that of a wind turbine [1].
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a good predictability — tidal flows can be predicted with accuracy years in advance, which is not the case for wind. River and man-made channel flows are also typically well predictable and dependable.
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a more discreet impact — visually and audibly, hydrokinetic turbines should be much more easily acceptable by the population. Indeed, when deployed on the seabed, they don't spoil the landscape and become essentially invisible.
[1] Considering a 4 knots (2m/s) water flow velocity and a wind speed of 25km/h (7m/s).
How it works
The use of wings undergoing an oscillating motion in both heaving and pitching is interesting in many engineering applications (energy extraction, propulsion, flow control).
In the current project where electricity production from water flow is targeted, work must be done by the water flow on the wings in order to maintain their oscillating motion. This work represents a fraction, typically less than 40%, of the kinetic energy associated with the flow velocity.
To assure that energy is being transferred from the water to the wings, the wings motion amplitudes and oscillating frequencies must be carefully tuned to make sure that the instantaneous angle of attack yields a resulting hydrodynamic force which tends to maintain the cyclic motion.
The wings oscillating motion is then mechanically converted to a rotating motion driving a shaft connected to an electric generator.
HAO-LAVAL research project
Several hydrokinetic turbine concepts are being developed around the world, most of them using horizontal axis rotor blades (as most modern wind turbines) or vertical axis rotor blades (as Darrieus-type wind turbines).
The HAO research project (Hydrolienne à Ailes Oscillantes: Oscillating-wings hydrokinetic turbine) from Laval University involves the use of rectangular lifting surfaces (wings) oscillating in a water flow. These oscillating wings replace the conventional rotor blades.
The water flow drives the oscillating motion of the wings whose alternate motion is transmitted to a rotating shaft connected to a generator.
The hydrodynamic forces driving the wings are also cyclic which allows reaching higher mean performances than the ones achievable with a rotor-blade-hydrokinetic turbine of similar size in the same flow.
Results based on extensive numerical simulations predict a greater hydrodynamic efficiency for oscillating-wings hydrokinetic turbines compared to rotor-blade hydrokinetic turbines.
In addition, the untwisted wings of an oscillating-wings turbine have a simpler geometry than typical rotor blades. Moreover, its rectangular extraction plane is much more suitable to seabed and riverbed, allowing shallow water deployment with the possibility to scale up the rated power by simply increasing the turbine wing span.