Publications associées à Moteur en étoile

Near-Zero Parasitic Shift Flexure Pivots Based on Coupled n-RRR Planar Parallel Mechanisms

Simon Nessim Henein, Florent Cosandier, Loïc Benoît Tissot-Daguette, Etienne Frédéric Gabriel Thalmann

Flexure pivots, which are widely used for precision mechanisms, generally have the drawback of presenting parasitic shifts accompanying their rotation. The known solutions for canceling these undesirable parasitic translations usually induce a loss in radi ...

2024

Power performance of a model floating wind turbine subjected to cyclic pitch motion: A wind tunnel study

Fernando Porté Agel, Guiyue Duan, Daniele Gattari

Wind tunnel experiments were performed with a miniature floating wind turbine model to study the effects of cyclic pitch motion on its power performance. The cyclic pitch motion was prescribed by two key parameters: pitch frequency and amplitude. The power ...

IOPscience2024

Estimating the non-dimensional energy of vortex rings by modelling their roll-up

Karen Ann J Mulleners, Guillaume de Guyon-Crozier

The non-dimensional energy of starting vortex rings typically converges to values around 0.33 when they are created by a piston-cylinder or a bluff body translating at a constant speed. To explore the limits of the universality of this value and to analyse ...

Cambridge University Press2022

Design and modelling of a tubular dielectric elastomer actuator with constrained radial displacement as a cardiac assist device

Yves Perriard, Yoan René Cyrille Civet, Armando Matthieu Walter, Jonathan André Jean-Marie Chavanne

In this paper, we propose an improvement of a dielectric elastomer actuator (DEA) based augmented aorta. The actuator is a multi-layered tubular DEA subject to the internal pressure of the blood. When activated in synchronisation with the heart, the DEA su ...

IOP PUBLISHING LTD2021

Adaptive HTAP through Elastic Resource Scheduling

Anastasia Ailamaki, Syed Mohammad Aunn Raza, Periklis Chrysogelos, Angelos Christos Anadiotis

Modern Hybrid Transactional/Analytical Processing (HTAP) systems use an integrated data processing engine that performs analytics on fresh data, which are ingested from a transactional engine. HTAP systems typically consider data freshness at design time, ...

2020

Adaptive HTAP through Elastic Resource Scheduling

Anastasia Ailamaki, Syed Mohammad Aunn Raza, Periklis Chrysogelos, Angelos Christos Anadiotis

Modern Hybrid Transactional/Analytical Processing (HTAP) systems use an integrated data processing engine that performs analytics on fresh data, which are ingested from a transactional engine. HTAP systems typically consider data freshness at design time, ...

ASSOC COMPUTING MACHINERY2020

Buckling of geometrically confined shells

Matteo Pezzulla

We study the periodic buckling patterns that emerge when elastic shells are subjected to geometric confinement. Residual swelling provides access to range of shapes (saddles, rolled sheets, cylinders, and spherical sections) which vary in their extrinsic a ...

ROYAL SOC CHEMISTRY2019

Radial-Force-Based Swirling Actuator with Surface-Permanent-Magnet Structure for Low-Speed High-Torque Applications

Adrien Jean-Michel Thabuis

This paper proposes a swirling actuator that utilizes the electromagnetic radial force and a swirling gear to generate rotational torque. This actuator converts the swirling motion to the rotational motion and is suitable for low-speed high-torque applicat ...

IEEE2019

Process integration as a tool for the improvement of cruise ships energy efficiency

François Maréchal, Francesco Baldi

The growing trend of the cruise ship industry, together with increasing concerns over its impact on the environment, makes these ships a much relevant target for efforts toward increasing ship energy efficiency, thus ultimately reducing fuel consumption an ...

2018

Design, modeling and experimental validation of a novel finned reciprocating compressor for Isothermal Compressed Air Energy Storage applications

Alfred Rufer, Mahbod Heidari

Considering the need for a reliable and environmentally friendly energy storage solution for addressing renewable energy intermittency issue and following the developments on Isothermal Compressed Air Energy Storage (I-CAES) systems, a new finned piston co ...

Pergamon-Elsevier Science Ltd2017

Turbocompressors for Domestic Heat Pumps – A Critical Review

Jürg Alexander Schiffmann, Jean-Baptiste Carré

Small-scale, oil-free radial compressors on gas lubricated bearings represent a promising alternative to state-of-the-art compressor technology for driving domestic sized heat pumps. The inherent characteristics of turbocompressors manage to fit the heat p ...

2017

ORC Driven Heat Pump Running on Gas Bearings for Domestic Applications: Proof of Concept and Thermo-Economic Improvement Potential

Jürg Alexander Schiffmann, Violette Mounier

ORC driven Heat Pumps (HP-ORC) offer a promising technology of thermally driven heat pumps (TDHPs) for domestic applications. Recently, a 40 kW HP-ORC unit based on gas supported turbomachinery has been investigated in which the ORC radial turbine drives t ...

2017

A Scala Library for Testing Student Assignments on Concurrent Programming

Mikaël Mayer, Ravichandhran Kandhadai Madhavan

We present a lightweight library for testing concurrent Scala programs by systematically exploring multiple interleavings between user-specified operations on shared objects. Our library is targeted at beginners of concurrent programming in Scala, runs on ...

Assoc Computing Machinery2016

Experimental investigation of a two-stage oil-free domestic Air/Water heat pump prototype powered by an oil-free high-speed twin-stage radial compressor rotating on gas bearings

Daniel Favrat, Jürg Alexander Schiffmann, Jean-Baptiste Carré

Domestic heat pumps have been identified as a key-technology to decrease the energy consumption of the domestic sector, which represents 29% of the world final energy consumption. Space & water heating represent more than two third of the domestic sector e ...

2016

Contribution to the Technique of Compressed Air Energy Storage : The Concept of Finned Piston

Mahbod Heidari

Development of intermittent solar and wind energies and the demand peak increase has made energy storage very important in energy policy. Thus, energy storage will play a key role in enabling the world to develop a low-carbon electricity system. An interes ...

EPFL2015

H2O: A Hands-free Adaptive Store

Anastasia Ailamaki, Ioannis Alagiannis

Modern state-of-the-art database systems are designed around a single data storage layout. This is a fixed decision that drives the whole architectural design of a database system, i.e., row-stores, column-stores. However, none of those choices is a univer ...

2014

Thermo-Electric Analogy Method for Computing Transient Heat Transfer in a New Reciprocating Finned Piston Compressor

John Richard Thome, Alfred Rufer, Mahbod Heidari

In the framework of Isothermal Compressed Air Energy Storage (CAES), a new finned piston compressor has been designed and realized at LEI laboratory in EPFL. This system comprises a series of concentric annuli’s fitting into each other compressing the air ...

2014

Dynamic Modeling and Simulation of Two-stage Compression Heat Pumps with Flash Economizer

Daniel Favrat, Jean-Baptiste Carré, Samuel Henchoz, Simon Gailledrat

Multistage heat pumps are one of the most efficient technologies for delivering heat at temperatures below 100°C, Thanks to their fairly high exergy efficiency. In the recent years the development of radial compressors mounted on gas bearings have unlock t ...

2013

Analysis and Development of a New Compressor Device Based on The New Finned Piston

Alfred Rufer, Mahbod Heidari

In the general frame of Compressed Air Energy Storage system (CAES), the LEI Laboratory of EPFL has introduced the concept of dry finned piston. The main goal is to achieve energy storage by means of compressed air thanks to high isothermal efficiency comp ...

2013

Modal Identification and Modeling of Bearings for Very High-Speed Rotors

Grégoire Dormond

Rotor-bearing systems take an important place in engineering applications and are used in many industrial systems: gas turbines, compressors, jet engines, machine-tool spindles, etc. The spindle is an essential component of manufacturing systems involving ...

EPFL2010