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SAM collecte, emmagasine, indexe, archive, et diffuse du matériel de recherche en format numérique.Thu, 19 Apr 2018 20:02:33 GMT2018-04-19T20:02:33ZSuccessive bifurcations in a fully three-dimensional open cavity flow
http://hdl.handle.net/10985/13014
PICELLA, F; LOISEAU, J.; LUSSEYRAN, f; ROBINET, j; CHERUBINI, s; PASTUR, l
Journal of Fluid Mechanics
The transition to unsteadiness of a three-dimensional open cavity flow is investigated
using the joint application of direct numerical simulations and fully three-dimensional
linear stability analyses, providing a clear understanding of the first two bifurcations
occurring in the flow. The first bifurcation is characterized by the emergence of
Taylor–Görtler-like vortices resulting from a centrifugal instability of the primary
vortex core. Further increasing the Reynolds number eventually triggers self-sustained
periodic oscillations of the flow in the vicinity of the spanwise end walls of the
cavity. This secondary instability causes the emergence of a new set of Taylor–Görtler
vortices experiencing a spanwise drift directed toward the spanwise end walls of the
cavity. While a two-dimensional stability analysis would fail to capture this secondary
instability due to the neglect of the lateral walls, it is the first time to our knowledge
that this drifting of the vortices can be entirely characterized by a three-dimensional
linear stability analysis of the flow. Good agreements with experimental observations
and measurements strongly support our claim that the initial stages of the transition
to turbulence of three-dimensional open cavity flows are solely governed by modal
instabilities.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/130142018-01-01T00:00:00ZPICELLA, FLOISEAU, J.LUSSEYRAN, fROBINET, jCHERUBINI, sPASTUR, lThe transition to unsteadiness of a three-dimensional open cavity flow is investigated
using the joint application of direct numerical simulations and fully three-dimensional
linear stability analyses, providing a clear understanding of the first two bifurcations
occurring in the flow. The first bifurcation is characterized by the emergence of
Taylor–Görtler-like vortices resulting from a centrifugal instability of the primary
vortex core. Further increasing the Reynolds number eventually triggers self-sustained
periodic oscillations of the flow in the vicinity of the spanwise end walls of the
cavity. This secondary instability causes the emergence of a new set of Taylor–Görtler
vortices experiencing a spanwise drift directed toward the spanwise end walls of the
cavity. While a two-dimensional stability analysis would fail to capture this secondary
instability due to the neglect of the lateral walls, it is the first time to our knowledge
that this drifting of the vortices can be entirely characterized by a three-dimensional
linear stability analysis of the flow. Good agreements with experimental observations
and measurements strongly support our claim that the initial stages of the transition
to turbulence of three-dimensional open cavity flows are solely governed by modal
instabilities.Five-phase SPM machine with electronic pole changing effect for marine propulsion
http://hdl.handle.net/10985/12999
ZAHR, Hussein; SCUILLER, Franck; SEMAIL, Eric
In this paper, the possibility of designing a fivephase Surface-mounted Permanent Magnet (SPM) machine with 20 slots and 8 poles for a low power marine propulsion system
is examined. Due to its particular winding and surface magnet design, the machine inherently offers an electronic pole changing effect from 3×4 pole pairs at low speed to 4 pole pairs at high speed. At high speed, in the constant power range, according to Finite Element Analysis, the Maximum Torque Per Ampere strategy appears not to be the right solution to minimize the whole machine losses (copper, iron and magnets). In particular,
a strategy that favors the 4-pole rotating field at high speed allows to mitigate the magnet losses, thus limiting the risk of magnet overheating.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/10985/129992016-01-01T00:00:00ZZAHR, HusseinSCUILLER, FranckSEMAIL, EricIn this paper, the possibility of designing a fivephase Surface-mounted Permanent Magnet (SPM) machine with 20 slots and 8 poles for a low power marine propulsion system
is examined. Due to its particular winding and surface magnet design, the machine inherently offers an electronic pole changing effect from 3×4 pole pairs at low speed to 4 pole pairs at high speed. At high speed, in the constant power range, according to Finite Element Analysis, the Maximum Torque Per Ampere strategy appears not to be the right solution to minimize the whole machine losses (copper, iron and magnets). In particular,
a strategy that favors the 4-pole rotating field at high speed allows to mitigate the magnet losses, thus limiting the risk of magnet overheating.Integrated Traction/Charge/Air Compression Supply using 3-Phase Split-windings Motor for Electric Vehicle
http://hdl.handle.net/10985/12998
LHOMME, Walter; DELARUE, Philippe; DOS SANTOS MORAES, Tiago Jose; NGUYEN, Ngac Ky; SEMAIL, Eric; CHEN, Keyu; SILVESTRE, Benedicte
Transactions on Power Electronics
High cost, no-ideal driving range and charge time limit electric vehicle market share. Facing these challenges, an in-tegrated motor drive/battery charger system has been proposed by Valeo. A further advancement, based on this system, is present in this paper; for the first time, the integration of traction, charging and air-compressor supply modes is proposed and tested by real-time experimentation. This integrated system is expected to in-crease the vehicle component compactness and power, therefore potentially reduce the cost and battery charging time. An overall and unique control scheme is detailed to achieve the three main operating modes: traction, charging and air-compressor supply modes. The real-time experimentation results show the system fea-sibility.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/129982018-01-01T00:00:00ZLHOMME, WalterDELARUE, PhilippeDOS SANTOS MORAES, Tiago JoseNGUYEN, Ngac KySEMAIL, EricCHEN, KeyuSILVESTRE, BenedicteHigh cost, no-ideal driving range and charge time limit electric vehicle market share. Facing these challenges, an in-tegrated motor drive/battery charger system has been proposed by Valeo. A further advancement, based on this system, is present in this paper; for the first time, the integration of traction, charging and air-compressor supply modes is proposed and tested by real-time experimentation. This integrated system is expected to in-crease the vehicle component compactness and power, therefore potentially reduce the cost and battery charging time. An overall and unique control scheme is detailed to achieve the three main operating modes: traction, charging and air-compressor supply modes. The real-time experimentation results show the system fea-sibility.Data-Driven Model Order Reduction for Magnetostatic Problem Coupled with Circuit Equations
http://hdl.handle.net/10985/12997
PIERQUIN, Antoine; HENNERON, Thomas; CLENET, Stephane
Transaction 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.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/129972018-01-01T00:00:00ZPIERQUIN, 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.Iterative Kriging-based Methods for Expensive Black-Box Models
http://hdl.handle.net/10985/12996
DENG, Siyang; EL BECHARI, Reda; BRISSET, Stéphane; CLENET, Stéphane
Transactions on magnetics
Reliability-Based Design Optimization (RBDO) in electromagnetic field problems requires the calculation of probability of failure leading to a huge computational cost in the case of expensive models. Three different RBDO approaches using kriging surrogate model are proposed to overcome this difficulty by introducing an approximation of the objective function and constraints. These methods use different infill sampling criteria (ISC) to add samples in the process of optimization or/and in the reliability analysis. Several enrichment criteria and strategies are compared in terms of number of evaluations and accuracy of the solution.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/129962018-01-01T00:00:00ZDENG, SiyangEL BECHARI, RedaBRISSET, StéphaneCLENET, StéphaneReliability-Based Design Optimization (RBDO) in electromagnetic field problems requires the calculation of probability of failure leading to a huge computational cost in the case of expensive models. Three different RBDO approaches using kriging surrogate model are proposed to overcome this difficulty by introducing an approximation of the objective function and constraints. These methods use different infill sampling criteria (ISC) to add samples in the process of optimization or/and in the reliability analysis. Several enrichment criteria and strategies are compared in terms of number of evaluations and accuracy of the solution.Influence of the Manufacturing Process of a Claw-Pole Alternator on Its Stator Shape and Acoustic Noise
http://hdl.handle.net/10985/12995
TAN-KIM, Antoine; HAGEN, Nicolas; LANFRANCHI, Vincent; CLENET, Stephane; COOREVITS, Thierry; MIPO, Jean-Claude; LEGRANGER, Jerome; PALLESCHI, Frédéric
Transactions on Industry Applications
This paper shows the influence of the manufacturing process of a claw-pole alternator on its acoustic noise. First, the stator welds and the assembly of the stator in the brackets are linked to deformations of the inner diameter of the stator. Then, the influences of these deformations on the magnetic forces and the subsequent acoustic noise are investigated. Results show that the deformations caused by the manufacturing process significantly increase the sound power level of particular orders.
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/10985/129952017-01-01T00:00:00ZTAN-KIM, AntoineHAGEN, NicolasLANFRANCHI, VincentCLENET, StephaneCOOREVITS, ThierryMIPO, Jean-ClaudeLEGRANGER, JeromePALLESCHI, FrédéricThis paper shows the influence of the manufacturing process of a claw-pole alternator on its acoustic noise. First, the stator welds and the assembly of the stator in the brackets are linked to deformations of the inner diameter of the stator. Then, the influences of these deformations on the magnetic forces and the subsequent acoustic noise are investigated. Results show that the deformations caused by the manufacturing process significantly increase the sound power level of particular orders.Five-Phase Bi-Harmonic PMSM Control under Voltage and Currents Limits
http://hdl.handle.net/10985/12994
ZAHR, Hussein; TRABELSI, Mohamed; SEMAIL, Eric; NGUYEN, Ngac Ky
For a particular five-phase synchronous machine, this paper investigates the sensitivity of a vectorial control strategy on the required peak phase voltage whose value is fundamental for the choice of the DC bus voltage. The specificity of the machine is that the first and third harmonic components of the back electromotive force (back-emf) have the same amplitude. As a consequence, the torque can be produced by one of them or both with suitable currents. This degree of freedom is interesting for optimizing the efficiency and generating high transient torque. However, using two harmonics having the same amplitude leads to a necessity to analyze the constraints on the required phase machine voltage. Considering a Maximum Torque Per Ampere (MTPA) strategy, the paper examines the impact of some parameters such as the phase shift between currents and back-emfs or the ratio between the third and the first harmonic of current on the torque and maximum voltage value. Experimental tests with a limited DC bus voltage have been carried out and compared to the results obtained by a Finite Element Analysis.
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/10985/129942017-01-01T00:00:00ZZAHR, HusseinTRABELSI, MohamedSEMAIL, EricNGUYEN, Ngac KyFor a particular five-phase synchronous machine, this paper investigates the sensitivity of a vectorial control strategy on the required peak phase voltage whose value is fundamental for the choice of the DC bus voltage. The specificity of the machine is that the first and third harmonic components of the back electromotive force (back-emf) have the same amplitude. As a consequence, the torque can be produced by one of them or both with suitable currents. This degree of freedom is interesting for optimizing the efficiency and generating high transient torque. However, using two harmonics having the same amplitude leads to a necessity to analyze the constraints on the required phase machine voltage. Considering a Maximum Torque Per Ampere (MTPA) strategy, the paper examines the impact of some parameters such as the phase shift between currents and back-emfs or the ratio between the third and the first harmonic of current on the torque and maximum voltage value. Experimental tests with a limited DC bus voltage have been carried out and compared to the results obtained by a Finite Element Analysis.Experimental investigation on the effect of load distribution on the performances of a counter-rotating axial-flow fan
http://hdl.handle.net/10985/12974
RAVELET, florent; BAKIR, farid; SARRAF, christophe; WANG, juan
experimental thermal and fluid science
In the design procedure of a counter-rotating axial-flow stage, parameters such as the angular velocity ratio and the repartition of the work performed by each rotors are to be chosen. In the present Article, three counter-rotating stages are designed to meet the same working point. These stages have different repartitions of load between the front and rear rotor, different angular velocity ratios or mean stagger angles of the blades of the front rotors. The stage global characteristics and the unsteady features of the flow between the counter-rotating rotors are measured and compared. The three systems all have satisfying overall performances at the design point. Strong differences are observed in the flow field at partial flow rates, the rear rotor reducing the hub recirculation. The behaviour at partial flow rates is thus triggered by the rear rotor characteristics. The best compromise is obtained with a repartition of the loading of 60% for the front rotor and 40% for the rear rotor, with almost equal angular velocities
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Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/129742018-01-01T00:00:00ZRAVELET, florentBAKIR, faridSARRAF, christopheWANG, juanIn the design procedure of a counter-rotating axial-flow stage, parameters such as the angular velocity ratio and the repartition of the work performed by each rotors are to be chosen. In the present Article, three counter-rotating stages are designed to meet the same working point. These stages have different repartitions of load between the front and rear rotor, different angular velocity ratios or mean stagger angles of the blades of the front rotors. The stage global characteristics and the unsteady features of the flow between the counter-rotating rotors are measured and compared. The three systems all have satisfying overall performances at the design point. Strong differences are observed in the flow field at partial flow rates, the rear rotor reducing the hub recirculation. The behaviour at partial flow rates is thus triggered by the rear rotor characteristics. The best compromise is obtained with a repartition of the loading of 60% for the front rotor and 40% for the rear rotor, with almost equal angular velocitiesDynamic recrystallization behaviour of spheroidal graphite iron. Application to cutting operations
http://hdl.handle.net/10985/12954
LE MERCIER, Kévin; WATREMEZ, Michel; PUCHI-CABRERA, Eli Saul; DUBAR, Laurent; GUERIN, Jean Daniel; FOUILLAND PAILLE, Laurence
Journal of Materials Processing Technology
To increase the competitiveness of manufacturing processes, numerical approaches are unavoidable. Nevertheless, a precise knowledge of the thermo-mechanical behaviour of the materials is necessary to simulate accurately these processes. Previous experimental studies have provided a limited information concerning dynamic recrystallization of spheroidal graphite iron under hot cutting operations. The purpose of this paper is to develop a constitutive model able to describe accurately the occurrence of this phenomenon. Compression tests are carried out using a Gleeble 3500 thermo-mechanical simulator to determine the hot deformation behaviour of spheroidal graphite iron at high strains. Once the activation range of the dynamic recrystallization process is assessed, a constitutive model taking into account this phenomenon is developed and implemented in the Abaqus/Explicit software. Finally, a specific cutting test and its finite element model are introduced. The ability of the numerical model to predict the occurrence of dynamic recrystallization is then compared to experimental observations.
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/10985/129542017-01-01T00:00:00ZLE MERCIER, KévinWATREMEZ, MichelPUCHI-CABRERA, Eli SaulDUBAR, LaurentGUERIN, Jean DanielFOUILLAND PAILLE, LaurenceTo increase the competitiveness of manufacturing processes, numerical approaches are unavoidable. Nevertheless, a precise knowledge of the thermo-mechanical behaviour of the materials is necessary to simulate accurately these processes. Previous experimental studies have provided a limited information concerning dynamic recrystallization of spheroidal graphite iron under hot cutting operations. The purpose of this paper is to develop a constitutive model able to describe accurately the occurrence of this phenomenon. Compression tests are carried out using a Gleeble 3500 thermo-mechanical simulator to determine the hot deformation behaviour of spheroidal graphite iron at high strains. Once the activation range of the dynamic recrystallization process is assessed, a constitutive model taking into account this phenomenon is developed and implemented in the Abaqus/Explicit software. Finally, a specific cutting test and its finite element model are introduced. The ability of the numerical model to predict the occurrence of dynamic recrystallization is then compared to experimental observations.Energy efficiency optimization of engine by frictional reduction of functional surfaces of cylinder ring-pack system
http://hdl.handle.net/10985/12941
MEZGHANI, Sabeur; DEMIRCI, Ibrahim; EL MANSORI, Mohamed; ZAHOUANI, Hassan
Tribology International
Friction reduction, lower oil consumption, and limitation of greenhouse gases emissions are the chief objectives of the automotive industry in order to improve the environmental efficiency of vehicle engines.
In this paper, a strategy for ring-pack friction reduction through cylinder liner finish optimization based on coupling instrumented honing experiments and numerical prediction of elastohydrodynamic friction is proposed.
The results show that honed surfaces produced by fine abrasion by honing stones yield the optimal elastohydrodynamic friction. They also demonstrate the limitations of ISO 13565 standard roughness parameters in giving a complete description of the functional performances of cylinder surface finishes.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10985/129412013-01-01T00:00:00ZMEZGHANI, SabeurDEMIRCI, IbrahimEL MANSORI, MohamedZAHOUANI, HassanFriction reduction, lower oil consumption, and limitation of greenhouse gases emissions are the chief objectives of the automotive industry in order to improve the environmental efficiency of vehicle engines.
In this paper, a strategy for ring-pack friction reduction through cylinder liner finish optimization based on coupling instrumented honing experiments and numerical prediction of elastohydrodynamic friction is proposed.
The results show that honed surfaces produced by fine abrasion by honing stones yield the optimal elastohydrodynamic friction. They also demonstrate the limitations of ISO 13565 standard roughness parameters in giving a complete description of the functional performances of cylinder surface finishes.