Publications related to Rotor (electric)

The effect of nacelle-to-rotor size on the wake of a miniature wind turbine

Fernando Porté Agel, Arslan Salim Dar, Rim Majzoub

Wind tunnel experiments are performed to investigate the effect of nacelle-to-rotor size on the wake of a wind turbine under different Reynolds numbers. Four different turbine configurations are tested, which vary in the rotor diameter and nacelle length a ...

IOP Science2024

Principle and Analysis of Radial-Force-Based Swirling Actuator for Low-Speed High-Torque Applications

Adrien Jean-Michel Thabuis

This article proposes a swirling actuator that uses the electromagnetic radial force and mechanical gears to generate rotational torque. The proposed actuator generates a rotating radial force between an inner stator and a swirler. The gears on the swirler ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Experimental Investigation of Enhanced Grooves for Herringbone Grooved Journal Bearings

Jürg Alexander Schiffmann, Patrick Hubert Wagner, Philipp Kaspar Bättig

This paper presents the results of a theoretical and experimental investigation of the potential of enhanced groove geometries to increase the bearing clearance of a Herringbone Grooved Journal Bearing (HGJB) supported rotor. The theoretical study investig ...

2022

Experimental and numerical investigation of the unbalance behavior of rigid rotors supported by spiral-grooved gas journal bearings

Jürg Alexander Schiffmann, Elia Iseli

The forced response of rigid rotors, supported by herringbone-grooved gas journal bearings are investigated numerically and experimentally. The rotor configurations are varied by using end cylinders, attached at both sides of the shaft. Three rotors with d ...

ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD2022

Balancing high-speed rotors at low speed using optimized parametric excitation and tuned nonlinear feedback

Amit Yedidia Dolev

The paper presents an improved slow-speed mass balancing procedure capable of reducing high-speed related imbalance. Parametric excitation is used to project the small imbalance forces onto a chosen mode of vibration, corresponding to a high critical rotat ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Modelling and Sensors for Magnetically-Levitated Disc Drives

Juan Patricio Tomás Peralta Fierro

The development of new industrial applications has diverted the focus of research towards compacter and faster rotatory drives. These requirements push the classical ball-bearings of electric motors to the limits in terms of operational lifetime and fricti ...

EPFL2022

Characterization and Verification of Eddy-Current Position Sensing for Magnetic Levitation

Yves Perriard, Sean Thomas, Juan Patricio Tomás Peralta Fierro

Magnetically-levitated drives are compelling in applications where the long-lifetime operation or process chamber encapsulation is a requirement. To exploit these advantages, contactless position sensors are needed to estimate the position of the rotor. Of ...

2021

Experimental Investigation of a Small-Scale Organic Rankine Cycle Turbo-Generator Supported on Gas-Lubricated Bearings

Jürg Alexander Schiffmann, Kévin Rosset

Waste heat recovery (WHR) is expected to contribute to reducing CO2 emissions from trucks. Organic Rankine cycle (ORC) systems show the highest potential for this application, but still lack efficient small-scale expansion devices, in practice. A novel tur ...

2021

Nonlinear study on a rigid rotor supported by herringbone grooved gas bearings: Theory and validation

Jürg Alexander Schiffmann, Patrick Hubert Wagner, Philipp Kaspar Bättig, Wanhui Liu

The nonlinear behavior of a rigid rotor supported by herringbone grooved journal gas bearings (HGJBs) was investigated in this study. The two-dimensional narrow groove theory (2D-NGT) was adopted to model the HGJBs. A set of integrated rotor-bearing state ...

2021

Unstable tilting motion of flexibly supported gas bearing bushings

Jürg Alexander Schiffmann, Philipp Kaspar Bättig

This paper presents measurements of the motion amplitudes from flexibly supported Herringbone Grooved Journal Bearing bushings. Measurements taken in four locations on the flexibly supported bearing bushing enable the distinction between the radial and the ...

2022

Rotor Position Estimation with Hall-Effect Sensors in Bearingless Drives

Yves Perriard, Juan Patricio Tomás Peralta Fierro

The estimation of rotor position is fundamental for the commissioning of magnetically-levitated drives. The sensors required for this measurement must be close to the rotor, often requiring constructive measures that may limit the application potential of ...

IEEE2020

Small scale very high speed slotless permanent magnet motors

Guillaume Paul-André Burnand

This research work has been triggered by an industrial project aimed at modelling and manufacturing a small-scale very high speed motor. Very high speed electrical motors offer the main advantage of reducing the size of a system. Indeed, at constant output ...

EPFL2020

Macroscopic polarization in the nominally ergodic relaxor state of lead magnesium niobate

Dragan Damjanovic, Lukas Riemer, Yang Li, Kanghyun Chu, Brahim Dkhil

Macroscopic polarity and its dynamic response to external electric fields and temperature in the nominally ergodic relaxor phase of pristine lead magnesium niobate crystals and ceramics, Pb(Mg1/3Nb2/3)O3 (PMN), were investigated. Dynamic pyroelectric measu ...

AIP American Institute of Physics2020

Small-scale organic Rankine cycle turbo-generator for waste heat recovery on truck engine

Kévin Rosset

Truck engine waste heat recovery (WHR) systems have been investigated for many years. Among them, organic Rankine cycle (ORC) systems show the highest potential, but still lack efficient small-scale expansion devices, in practice. Proposed expanders are of ...

EPFL2020

An Instrumented High-Speed Rotor with Embedded Telemetry for The Continuous Spatial Pressure Profile Measurement in Gas Lubricated Bearings: A Proof of Concept

Jürg Alexander Schiffmann, Karim Magdi Zakaria Abdelrahman Shalash

Pressure is one of the constitutional quantities governing the flow field in gas lubricated bearings. Knowledge of the pressure is of principal importance in the fundamental understanding of such bearings and for the calibration of reduced order models. Th ...

2020

MRI after successful eyeWatch(TM) implantation

Nikolaos Stergiopoulos, André Mermoud, Sylvain Roy, Adan Villamarin

The eyeWatch(TM) is a new glaucoma drainage device that includes an adjustable mechanism that can vary the resistance to aqueous humor outflow during the postoperative period to reduce the burden of postoperative intraocular pressure (IOP) management. The ...

SAGE PUBLICATIONS LTD2020

Integrated, Eddy-Current-Based Sensing of Rotor Position for Magnetic Levitation

Yves Perriard, Sean Thomas, Juan Patricio Tomás Peralta Fierro

Magnetically-levitated drives are compelling in applications where long-lifetime operation or process chamber encapsulation is a requirement. To exploit these advantages, contactless position sensors are needed for position information of the rotor. Off-th ...

IEEE2020

Electrical effects in winding of large electrical ac machines application to advanced large size DFIM

Frédéric Michael Maurer

To meet the electrical grid's demand on pump power variation, GE Renewable Energy develops since 10 years variable speed machines (also called Doubly Fed Induction Generators or DFIG). Within turbogenerators, the phenomenon of circulating currents in Roebe ...

EPFL2019

An Instrumented High-Speed Rotor With Embedded Telemetry For The Continuous Spatial Pressure Profile Measurement In Gas Lubricated Bearings: A Proof Of Concept

Jürg Alexander Schiffmann, Karim Magdi Zakaria Abdelrahman Shalash

Gas lubricated bearings are capable of supporting high speed rotors with satisfactory load capacities. Pressure is one of the constitutional quantities governing the flow field in gas lubricated bearings. Knowledge of the pressure is of principal importanc ...

Amer Soc Mechanical Engineers2019

Progress in disruption prevention for ITER

Olivier Sauter, Mengdi Kong, Alessandro Pau, Francesca Maria Poli, Umar Sheikh, Ji Hyun Kim

Key plasma physics and real-time control elements needed for robustly stable operation of high fusion power discharges in ITER have been demonstrated in recent research worldwide. Recent analysis has identified the current density profile as the main drive ...

IOP Publishing Ltd2019