Papers by Jean-Paul Yonnet
dc Grenoble (V.A. CNRS n0355) ENSIEG-B.P. 46 38402 St Martin d'H"res Cedex-FRANCE This article pr... more dc Grenoble (V.A. CNRS n0355) ENSIEG-B.P. 46 38402 St Martin d'H"res Cedex-FRANCE This article presents the limits of a 2D modelling of a real 3D electromagnetic problem, on an analytically known case. For each kind of calculation (nunierical and analytical), we have separated different kinds of errors. Consequently, we sueceeded in defining a minimal length allowing the user to obtain bctter results by a 2D modell ing than by a 3D one.
Analytical Calculation of Cuboïdal Magnet Interactions in 3D
A synthesis of all the analytical expressions of the interaction energy, force components and tor... more A synthesis of all the analytical expressions of the interaction energy, force components and torque components is presented. It allows the analytical calculation of all the interactions when the magnet izations are in any direction. The 3D analytical expressions are difficult to obta in, but the torque and force expressions are very simpl e to use.
A differential magnetic position sensor
Sensors and Actuators A: Physical, 2000
This paper presents a new structure of a magnetic sensor. The output signal is proportional to th... more This paper presents a new structure of a magnetic sensor. The output signal is proportional to the angular position. The originality of the structure comes from its design that permits the measurement of the sum of two magnetic inductions which is a constant. This allows the output signal to be insensitive to some external parameters such as the temperature.
Sensor Letters, 2009
Up to now, the analytical calculation has been made only when the magnets own parallel magnetizat... more Up to now, the analytical calculation has been made only when the magnets own parallel magnetization directions. We have succeeded in two new results of first importance for the analytical calculation: the torque between two magnets, and the force components and torque when the magnetization directions are perpendicular. The last result allows the analytical calculation of the interactions when the magnetizations are in all the directions.
Plasma confinement by a rotating magnet device
Journal of Magnetism and Magnetic Materials, 1990
An original rotating magnet system has been developed to enhanced the RIE process. It is built wi... more An original rotating magnet system has been developed to enhanced the RIE process. It is built with synchronously rotating bar-shaped magnets, which create a travelling magnetic field of high intensity. This paper explains why the interaction torque between the magnets is very small, and how it is possible to obtain a high magnetic field in the useful area.
A partially passive magnetic suspension for a discoidal wheel
Journal of Applied Physics, 1988
For discoidal or annular rotors, a magnetic suspension made only with one passive axial bearing a... more For discoidal or annular rotors, a magnetic suspension made only with one passive axial bearing and one active radial bearing is very well adapted. This suspension is relatively simple, and can operate without any additional damping system. A flywheel prototype has been built to test this magnetic suspension. The rotor is a 300-mm-diam aluminum disk (7.3 kg weight) rotating at
A magnetic coupling without parasitic force for measuring devices
Journal of Applied Physics, 1994
Original structures of permanent magnet couplings have been studied. They can transmit a torque w... more Original structures of permanent magnet couplings have been studied. They can transmit a torque without creating forces or stiffness between the driver and the driven part. Except for torque, the two parts are in indifferent equilibrium. These couplings have been designed for measuring devices in which they exert no force on the bearings but they can be used in other
IEEE Transactions on Magnetics, 2000
Most of the systems working by magnet interactions can be calculated by superposition of the inte... more Most of the systems working by magnet interactions can be calculated by superposition of the interactions between parallelepiped elementary magnets. Each elementary magnet is submitted to a force and a torque. By 3-D fully analytical calculation, up to now, only the force components problem has been solved. It was published for the first time in 1984. Until now, the torque components have never been analytically calculated because of the angular derivation. We have solved it, so that now all the interactions (energy, three forces components, and three torque components) can be expressed by analytical formulations. The only hypothesis is that the magnetizations J and J ' are supposed to be rigid and uniform in each magnet. The analytical calculation is made by replacing magnetizations by distributions of magnetic charges on the magnet poles. The torque is calculated for rotational movement of the second magnet around its center. The three components of the torque are written with functions based on logarithm and arc-tangent. The results have been verified and validated by comparison with finite-element calculation. Analytical calculation owns many advantages in comparison with other calculation methods. The 3-D analytical expressions are difficult to obtain, but the expressions of energy, force, and torque are very simple to use. For example, the analytical expression can be included in optimization software allowing to directly obtaining the shape optimization by a fast way.
Elaboration of contactless magnetic temperature sensors
Structure comparison of buried permanent magnet synchronous motors for flux weakening operation
ABSTRACT
Les récentes méthodes d'imagerie IRM parallèle (SENSE et SMASH) nécessitent une bonne connaissanc... more Les récentes méthodes d'imagerie IRM parallèle (SENSE et SMASH) nécessitent une bonne connaissance de la sensibilité des antennes. Celle ci est généralement mesurée lors d'une phase de calibration, ou estimée par filtrage adaptatif spatio-temporel si l'on dispose d'une série d'acquisitions (TSENSE). Nous proposons une formulation du problème en termes de séparation aveugle de sources : une analyse en composantes indépendantes (ICA) permet alors d'extraire les informations de sensibilité des antennes à partir d'une seule acquisition. Des résultats de simulations sont présentés, démontrant l'intérêt de cette nouvelle méthode que nous nommerons ICASENSE.
This paper proposes a review of the magnetostatic moments method (MoM) applied to model electroma... more This paper proposes a review of the magnetostatic moments method (MoM) applied to model electromagnetic devices. This method is now well-known for its "light weight" and its simplicity of implementation. Its main advantages are the nonrequirement of an air region mesh and a coarse mesh of the ferromagnetic material. It leads to very fast resolution and very accurate field, force, and moment computations. The paper proposes a state of the art of this approach and shows some efficient realizations.
Design of a NMR sensor working in inhomogeneous field
Numerical Optimization of the Torque of a Permanent Magnet Synchronous Coaxial Coupling
... Numerical Optimization of the Torque of a Permanent Magnet Synchronous Coaxial Coupling.Houss... more ... Numerical Optimization of the Torque of a Permanent Magnet Synchronous Coaxial Coupling.Houssem Bouchekara 1 , Jean-Paul Yonnet 1 , Afef Kedous-Lebouc 1 , Cédric Dupuis 1 , Jean-Louis Coulomb 1. (11/05/2008). ... Contributeur : Sylvie Garcia <>. ...
Diversity of Mediteranean magnetotactic bacteria
Current Measurement with a GMI Sensor
Modélisation et Optimisation d'un Système Rotatif de Réfrigération Magnétique à Cycle Thermique Direct
Recent development in magnetic refrigeration in Grenoble: from materials to applications
Comparison of magnetic field sources for magnetic refrigeration at room temperature
Challenges for the implementation of magnetocaloric materials in cooling systems
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Papers by Jean-Paul Yonnet