Fluides et systèmes énergétiques (FISE)
http://hdl.handle.net/10985/174
2018-03-11T16:51:57ZModel Order Reduction of Electrical Machines with Multiple Inputs
http://hdl.handle.net/10985/12755
FARZAM FAR, M.; BELAHCEN, A.; RASILO, P.; CLENET, S.; PIERQUIN, A.
Transactions on Industry Applications
In this paper, proper orthogonal decomposition method is employed to build a reduced-order model from a high-order nonlinear permanent magnet synchronous machine
model with multiple inputs. Three parameters are selected as the multiple inputs of the machine. These parameters are terminal current, angle of the terminal current, and rotation
angle. To produce the lower-rank system, snapshots or instantaneous system states are projected onto a set of orthonormal basis functions with small dimension. The reduced
model is then validated by comparing the vector potential, flux density distribution, and torque results of the original model,which indicates the capability of using the proper orthogonal decomposition method in the multi-variable input problems. The developed methodology can be used for fast simulations of the machine.
2017-01-01T00:00:00ZFARZAM FAR, M.BELAHCEN, A.RASILO, P.CLENET, S.PIERQUIN, A.In this paper, proper orthogonal decomposition method is employed to build a reduced-order model from a high-order nonlinear permanent magnet synchronous machine
model with multiple inputs. Three parameters are selected as the multiple inputs of the machine. These parameters are terminal current, angle of the terminal current, and rotation
angle. To produce the lower-rank system, snapshots or instantaneous system states are projected onto a set of orthonormal basis functions with small dimension. The reduced
model is then validated by comparing the vector potential, flux density distribution, and torque results of the original model,which indicates the capability of using the proper orthogonal decomposition method in the multi-variable input problems. The developed methodology can be used for fast simulations of the machine.Application of the Proper Generalized Decomposition to Solve MagnetoElectric Problem
http://hdl.handle.net/10985/12754
HENNERON, Thomas; CLENET, Stéphane
Transaction on Magnetics
Among the model order reduction techniques, the Proper Generalized Decomposition (PGD) has shown its efficiency to solve a large number of engineering problems. In this article, the PGD approach is applied to solve a multi-physics problem based on a magnetoelectric device. A reduced model is developed to study the device in its environment based on an Offline/Online approach. In the Offline step, two specific
imulations are performed in order to build a PGD reduced model. Then, we obtain a model very well fitted to study in the Online stage the influence of parameters like the frequency or the load. The reduced model of the device is coupled with an electric load (R-L) to illustrate the possibility offered by the PGD.
2018-01-01T00:00:00ZHENNERON, ThomasCLENET, StéphaneAmong the model order reduction techniques, the Proper Generalized Decomposition (PGD) has shown its efficiency to solve a large number of engineering problems. In this article, the PGD approach is applied to solve a multi-physics problem based on a magnetoelectric device. A reduced model is developed to study the device in its environment based on an Offline/Online approach. In the Offline step, two specific
imulations are performed in order to build a PGD reduced model. Then, we obtain a model very well fitted to study in the Online stage the influence of parameters like the frequency or the load. The reduced model of the device is coupled with an electric load (R-L) to illustrate the possibility offered by the PGD.Proper Generalized Decomposition Applied on a Rotating Electrical Machine
http://hdl.handle.net/10985/12734
MONTIER, Laurent; HENNERON, Thomas; CLENET, Stephane; GOURSAUD, Benjamin
Transactions on magnetics
The Proper Generalized Decomposition (PGD) is a model order reduction method which allows to reduce the computational time of a numerical problem by seeking for a separated representation of the solution. The PGD has been already applied to study an electrical machine but at standstill without accounting the motion of the rotor. In this paper, we propose a method to account for the rotation in the PGD approach in order to build an efficient metamodel of an electrical machine. Then, the machine metamodel will be coupled to its electrical and mechanical environment in order to obtain accurate results with an acceptable computational time on a full simulation.
2018-01-01T00:00:00ZMONTIER, LaurentHENNERON, ThomasCLENET, StephaneGOURSAUD, BenjaminThe Proper Generalized Decomposition (PGD) is a model order reduction method which allows to reduce the computational time of a numerical problem by seeking for a separated representation of the solution. The PGD has been already applied to study an electrical machine but at standstill without accounting the motion of the rotor. In this paper, we propose a method to account for the rotation in the PGD approach in order to build an efficient metamodel of an electrical machine. Then, the machine metamodel will be coupled to its electrical and mechanical environment in order to obtain accurate results with an acceptable computational time on a full simulation.Discontinuity of lift on a hydrofoil in reversed flow for tidal turbine Application
http://hdl.handle.net/10985/12715
MARCHAND, Jean-Baptiste; ASTOLFI, Jacques André; BOT, Patrick
European Journal of Mechanics B/Fluids
This work presents an experimental investigation of a hydrofoil in reversed flow configuration in the context of marine current turbine development. Experiments consist in hydrodynamic force measurements and PIV flow observations on a NACA 0015 hydrofoil, at 5 × 105 Reynolds number. The hydrofoil in reversed flow produces a higher lift than in the classical forward flow for very low angles of attack and proved to be relatively efficient for an angle of attack lower than 10°, despite a much higher drag than the same foil in direct flow. Moreover, the lift coefficient shows a discontinuity with
an hysteresis effect when the angle of attack is varied up and down around zero-degree. It is shown that the sharp leading edge generates an early Leading Edge Separation Bubble on one side (suction side) even for vanishing angles of attack. This separation bubble triggers the transition to turbulence of the boundary layer on the suction side while the pressure side boundary layer remains laminar. As a consequence, separation on the rounded trailing edge occurs farther downstream on the (turbulent) suction side compared to the (laminar) pressure side. The Leading Edge Separation Bubble and the inherent up–down asymmetry in the boundary layer regime are responsible for the lift singularity.
2017-01-01T00:00:00ZMARCHAND, Jean-BaptisteASTOLFI, Jacques AndréBOT, PatrickThis work presents an experimental investigation of a hydrofoil in reversed flow configuration in the context of marine current turbine development. Experiments consist in hydrodynamic force measurements and PIV flow observations on a NACA 0015 hydrofoil, at 5 × 105 Reynolds number. The hydrofoil in reversed flow produces a higher lift than in the classical forward flow for very low angles of attack and proved to be relatively efficient for an angle of attack lower than 10°, despite a much higher drag than the same foil in direct flow. Moreover, the lift coefficient shows a discontinuity with
an hysteresis effect when the angle of attack is varied up and down around zero-degree. It is shown that the sharp leading edge generates an early Leading Edge Separation Bubble on one side (suction side) even for vanishing angles of attack. This separation bubble triggers the transition to turbulence of the boundary layer on the suction side while the pressure side boundary layer remains laminar. As a consequence, separation on the rounded trailing edge occurs farther downstream on the (turbulent) suction side compared to the (laminar) pressure side. The Leading Edge Separation Bubble and the inherent up–down asymmetry in the boundary layer regime are responsible for the lift singularity.Transducteur adapté à la génération de forces en fonction de la vitesse d'écoulement d'un fluide
http://hdl.handle.net/10985/12674
BOT, Patrick
L’invention concerne un dispositif détecteur d’une vitesse seuil de déplacement d’un fluide, le dispositif détecteur comprenant un transducteur et configuré pour exercer une première force non nulle dans une première direction lorsque la vitesse du fluide est inférieure à la vitesse seuil et pour exercer une seconde force non nulle dans une seconde direction lorsque la vitesse du fluide est supérieure à la vitesse seuil , la première et la seconde direction étant identiques ou sensiblement identiques et la première et la deuxième force étant dirigées dans des sens opposés.
2017-01-01T00:00:00ZBOT, PatrickL’invention concerne un dispositif détecteur d’une vitesse seuil de déplacement d’un fluide, le dispositif détecteur comprenant un transducteur et configuré pour exercer une première force non nulle dans une première direction lorsque la vitesse du fluide est inférieure à la vitesse seuil et pour exercer une seconde force non nulle dans une seconde direction lorsque la vitesse du fluide est supérieure à la vitesse seuil , la première et la seconde direction étant identiques ou sensiblement identiques et la première et la deuxième force étant dirigées dans des sens opposés.Characterizing Porous Media with the Yield Stress Fluids Porosimetry Method
http://hdl.handle.net/10985/12575
RODRIGUEZ DE CASTRO, Antonio; OMARI, abdelaziz; AHMADI-SENICHAULT, Azita; SAVIN, Sabine; MADARIAGA, Luis-Fernando
Transport in Porous Media
A new data analyzing method to characterize pore size distribution (PSD) of porous media was recently presented in the context of an international consensus on the need to develop alternatives to toxic mercury porosimetry. It consists in measuring the flow rate Q at several pressure gradients ∇P during flowexperiments of yield stress fluids through porous media. In the present work, the PSD of different types of porous media is determined with this new technique and the obtained results are compared with those provided by mercury porosimetry. A series of experiments using a given yield stress fluid with different porous mediawere carried out in order to study the relevance of the obtained PSD.Besides, the critical aspects conditioning the experimental performance of the method were also identified and assessed.
2016-01-01T00:00:00ZRODRIGUEZ DE CASTRO, AntonioOMARI, abdelazizAHMADI-SENICHAULT, AzitaSAVIN, SabineMADARIAGA, Luis-FernandoA new data analyzing method to characterize pore size distribution (PSD) of porous media was recently presented in the context of an international consensus on the need to develop alternatives to toxic mercury porosimetry. It consists in measuring the flow rate Q at several pressure gradients ∇P during flowexperiments of yield stress fluids through porous media. In the present work, the PSD of different types of porous media is determined with this new technique and the obtained results are compared with those provided by mercury porosimetry. A series of experiments using a given yield stress fluid with different porous mediawere carried out in order to study the relevance of the obtained PSD.Besides, the critical aspects conditioning the experimental performance of the method were also identified and assessed.Wind tunnel investigation of dynamic trimming on upwind sail aerodynamics
http://hdl.handle.net/10985/12560
AUBIN, Nicolas; AUGIER, Benoit; SACHER, Matthieu; BOT, Patrick; HAUVILLE, Frédéric; FLAY, Richard G.J.
Journal of Sailing Technology
An experiment was performed in the Yacht Research Unit’s Twisted Flow Wind Tunnel
(University of Auckland) to test the effect of dynamic trimming on three IMOCA 60 inspired mainsail models in an upwind ( AW = 60°) unheeled configuration. This study presents dynamic fluid structure interaction results in well controlled conditions (wind, sheet length) with a dynamic trimming system. Trimming oscillations are done around an optimum value of CFobj previously found with a static trim. Different oscillation amplitudes and frequencies of trimming are investigated. Measurements
are done with a 6 component force balance and a load sensor giving access to the unsteady mainsail sheet load. The driving CFx and optimization target CFobj coefficient first decrease at low reduced frequency fr for quasi-steady state then increase, becoming higher than the static state situation. The driving force CFx and the optimization target coefficient CFobj show an optimum for the
three different design sail shapes located at fr = 0.255. This optimum is linked to the power transmitted to the rig and sail system by the trimming device. The effect of the camber of the design shape is also investigated. The flat mainsail design benefits more than the other mainsail designs from the dynamic trimming compared to their respective static situtation. This study presents dynamic results that cannot be accurately predicted with a quasi-static approach. These results are therefore valuable for future FSI numerical tools validations in unsteady conditions.
2017-01-01T00:00:00ZAUBIN, NicolasAUGIER, BenoitSACHER, MatthieuBOT, PatrickHAUVILLE, FrédéricFLAY, Richard G.J.An experiment was performed in the Yacht Research Unit’s Twisted Flow Wind Tunnel
(University of Auckland) to test the effect of dynamic trimming on three IMOCA 60 inspired mainsail models in an upwind ( AW = 60°) unheeled configuration. This study presents dynamic fluid structure interaction results in well controlled conditions (wind, sheet length) with a dynamic trimming system. Trimming oscillations are done around an optimum value of CFobj previously found with a static trim. Different oscillation amplitudes and frequencies of trimming are investigated. Measurements
are done with a 6 component force balance and a load sensor giving access to the unsteady mainsail sheet load. The driving CFx and optimization target CFobj coefficient first decrease at low reduced frequency fr for quasi-steady state then increase, becoming higher than the static state situation. The driving force CFx and the optimization target coefficient CFobj show an optimum for the
three different design sail shapes located at fr = 0.255. This optimum is linked to the power transmitted to the rig and sail system by the trimming device. The effect of the camber of the design shape is also investigated. The flat mainsail design benefits more than the other mainsail designs from the dynamic trimming compared to their respective static situtation. This study presents dynamic results that cannot be accurately predicted with a quasi-static approach. These results are therefore valuable for future FSI numerical tools validations in unsteady conditions.Fluid Structure Interaction of Yacht Sails in the Unsteady Regime
http://hdl.handle.net/10985/12555
AUGIER, Benoit; BOT, Patrick; HAUVILLE, Frédéric; DURAND, Mathieu
The dynamic Fluid Structure Interaction (FSI) of yacht sails submitted to a harmonic pitching motion is numerically investigated to address both issues of aerodynamic unsteadiness and structural deformation. The model consists in an implicit dynamic coupling algorithm between a Vortex Lattice Method model for the aerodynamics and a Finite Element Method model for the structure dynamics. It is shown that the dynamic
behaviour of a sail plan subject to yacht motion clearly deviates from the quasi-steady theory. The aerodynamic forces oscillate with phase shifts with respect to the
motion. This results in hysteresis phenomena, which show aerodynamic equivalent damping and stiffening effects of the unsteady behaviour. The area of the
hysteresis loop corresponds to the amount of energy exchanged by the system and increases with the motion reduced frequency and amplitude. In the case of a rigid
structure, the aerodynamic forces oscillations and the exchanged energy are lower than for a flexible structure.
2013-01-01T00:00:00ZAUGIER, BenoitBOT, PatrickHAUVILLE, FrédéricDURAND, MathieuThe dynamic Fluid Structure Interaction (FSI) of yacht sails submitted to a harmonic pitching motion is numerically investigated to address both issues of aerodynamic unsteadiness and structural deformation. The model consists in an implicit dynamic coupling algorithm between a Vortex Lattice Method model for the aerodynamics and a Finite Element Method model for the structure dynamics. It is shown that the dynamic
behaviour of a sail plan subject to yacht motion clearly deviates from the quasi-steady theory. The aerodynamic forces oscillate with phase shifts with respect to the
motion. This results in hysteresis phenomena, which show aerodynamic equivalent damping and stiffening effects of the unsteady behaviour. The area of the
hysteresis loop corresponds to the amount of energy exchanged by the system and increases with the motion reduced frequency and amplitude. In the case of a rigid
structure, the aerodynamic forces oscillations and the exchanged energy are lower than for a flexible structure.Modal Analysis of Pressures on a Full-Scale Spinnaker
http://hdl.handle.net/10985/12535
DEPARDAY, Julien; BOT, Patrick; HAUVILLE, Frédéric; AUGIER, Benoit; RABAUD, Marc; MOTTA, Dario; LE PELLEY, David
Journal of Sailing Technology
While sailing offwind, the trimmer typically adjusts the downwind sail “on the verge of luffing”, occasionally letting the luff of the sail flap. Due to the unsteadiness of the spinnaker itself, maintaining the luff on the verge of luffing requires continual adjustments. The propulsive force generated by the offwind sail depends on this trimming and is highly fluctuating. During a flapping sequence, the aerodynamic load can fluctuate by 50% of the average load. On a J/80 class yacht, we simultaneously
measured time-resolved pressures on the spinnaker, aerodynamic loads, boat data and wind data. Significant spatio-temporal patterns were detected in the pressure distribution. In this paper we present averages and main fluctuations of pressure distributions and of load coefficients for different apparent wind angles as well as a refined analysis of pressure fluctuations, using the Proper Orthogonal Decomposition (POD) method. POD shows that pressure fluctuations due to luffing of
the spinnaker can be well represented by only one proper mode related to a unique spatial pressure pattern and a dynamic behavior evolving with the Apparent Wind Angles. The time evolution of this proper mode is highly correlated with load fluctuations. Moreover, POD can be employed to filter the measured pressures more efficiently than basic filters. The reconstruction using the first few modes makes it possible to restrict the flapping analysis to the most energetic part of the signal and remove insignificant variations and noises. This might be helpful for comparison with other measurements
and numerical simulations.
2017-01-01T00:00:00ZDEPARDAY, JulienBOT, PatrickHAUVILLE, FrédéricAUGIER, BenoitRABAUD, MarcMOTTA, DarioLE PELLEY, DavidWhile sailing offwind, the trimmer typically adjusts the downwind sail “on the verge of luffing”, occasionally letting the luff of the sail flap. Due to the unsteadiness of the spinnaker itself, maintaining the luff on the verge of luffing requires continual adjustments. The propulsive force generated by the offwind sail depends on this trimming and is highly fluctuating. During a flapping sequence, the aerodynamic load can fluctuate by 50% of the average load. On a J/80 class yacht, we simultaneously
measured time-resolved pressures on the spinnaker, aerodynamic loads, boat data and wind data. Significant spatio-temporal patterns were detected in the pressure distribution. In this paper we present averages and main fluctuations of pressure distributions and of load coefficients for different apparent wind angles as well as a refined analysis of pressure fluctuations, using the Proper Orthogonal Decomposition (POD) method. POD shows that pressure fluctuations due to luffing of
the spinnaker can be well represented by only one proper mode related to a unique spatial pressure pattern and a dynamic behavior evolving with the Apparent Wind Angles. The time evolution of this proper mode is highly correlated with load fluctuations. Moreover, POD can be employed to filter the measured pressures more efficiently than basic filters. The reconstruction using the first few modes makes it possible to restrict the flapping analysis to the most energetic part of the signal and remove insignificant variations and noises. This might be helpful for comparison with other measurements
and numerical simulations.Data-Driven Model Order Reduction for Magnetostatic Problem Coupled with Circuit Equations
http://hdl.handle.net/10985/12497
PIERQUIN, Antoine; HENNERON, Thomas; CLENET, stephane
Transactions on magnetics
Among the model order reduction techniques, the Proper Orthogonal Decomposition (POD) has shown its efficiency to solve magnetostatic and magneto-quasistatic problems in the time domain. However, the POD is intrusive in the sense that it requires the extraction of the matrix system of the full model to build the reduced model. To avoid this extraction, nonintrusive approaches like the Data Driven (DD) methods enable to approximate the reduced model without the access to the full matrix system. In this article, the DD-POD method is applied to build a low dimensional system to solve a magnetostatic problem coupled with electric circuit equations.
2017-01-01T00:00:00ZPIERQUIN, AntoineHENNERON, ThomasCLENET, stephaneAmong the model order reduction techniques, the Proper Orthogonal Decomposition (POD) has shown its efficiency to solve magnetostatic and magneto-quasistatic problems in the time domain. However, the POD is intrusive in the sense that it requires the extraction of the matrix system of the full model to build the reduced model. To avoid this extraction, nonintrusive approaches like the Data Driven (DD) methods enable to approximate the reduced model without the access to the full matrix system. In this article, the DD-POD method is applied to build a low dimensional system to solve a magnetostatic problem coupled with electric circuit equations.