Publications related to Turbofan

Smart Acoustic Lining for UHBR Technologies Engine Part 1: Design of an Electroacoustic Liner and Experimental Characterization Under Flow in Rectangular Cross-Section Ducts

The new generation of Ultra-High-By-Pass-Ratio (UHBR) turbofan engine while considerably reducing fuel consumption, threatens higher noise levels at low frequencies because of its larger diameter, lower number of blades and rotational speed. This is accomp ...

American Institute of Aeronautics and Astronautics2024

Domain adaptation via alignment of operation profile for Remaining Useful Lifetime prediction

Olga Fink, Ismail Nejjar, Mengjie Zhao

Effective Prognostics and Health Management (PHM) relies on accurate prediction of the Remaining Useful Life (RUL). Data-driven RUL prediction techniques rely heavily on the representativeness of the available time-to-failure trajectories. Therefore, these ...

2024

The Advection Boundary Law in presence of mean-flow and spinning modes

In the attempt to reduce fuel consumption, a new generation of Ultra-High-By-Pass-Ratio (UHBR) turbofans have been introduced in the aeronautic industry which are structurally noisier especially at lower frequencies, because of their larger diameter, lower ...

SPIE2024

Wind turbine wake superposition under pressure gradient

Fernando Porté Agel, Arslan Salim Dar

We investigate the effect of pressure gradient on the cumulative wake of multiple turbines in wind tunnel experiments spanning across a range of adverse pressure gradient (APG), zero pressure gradient (ZPG), and favorable pressure gradient (FPG). Compared ...

2024

Robust tunable acoustic impedance control on electroacoustic resonators for aircraft noise reduction

Maxime Volery

Air traffic noise emissions are responsible for a significant part of the overall environmental noise, especially in the vicinity of airports. Exposure to environmental noise is known to negatively impact health and to be associated with cardiovascular dis ...

EPFL2023

Indication of 310-Helix Structure in Gas-Phase Neutral Pentaalanine

Vasyl Yatsyna

We investigate the gas-phase structure of the neutral pentaalanine peptide. The IR spectrum in the 340-1820 cm-1 frequency range is obtained by employing supersonic jet cooling, infrared multiphoton dissociation, and vacuum-ultraviolet action spectroscopy. ...

AMER CHEMICAL SOC2023

Uncertainty quantification in machine learning for engineering design and health prognostics: A tutorial

Olga Fink, Luca Biggio

On top of machine learning (ML) models, uncertainty quantification (UQ) functions as an essential layer of safety assurance that could lead to more principled decision making by enabling sound risk assessment and management. The safety and reliability impr ...

2023

Smart acoustic lining for UHBR technologies engine: from the design of an electroacoustic metasurface to experimental characterization under flow

Hervé Lissek, Maxime Volery

The SALUTE project aims at evaluating performance of electroacoustic metasurface, employing a surface array of controlled electroacoustic actuators, for smart acoustic lining under grazing turbulent flow to be used in UHBR Technologies Engines. Theoretical ...

Society of Photo-Optical Instrumentation Engineers (SPIE)2023

Locomotion of Sensor‐Integrated Soft Robotic Devices Inside Sub‐Millimeter Arteries with Impaired Flow Conditions

Diego Ghezzi, Mahmut Selman Sakar, Lorenzo Francesco John Noseda, Amit Yedidia Dolev, Lucio Feo Pancaldi-Giubbini, Adele Fanelli

One of the grand challenges in interventional cardiology and neuroradiology is to minimize the operation time and risk of damage during catheterization. These two factors drastically increase if the target location resides in small and tortuous vessels. Fl ...

Wiley2022

Real-time model calibration with deep reinforcement learning

Olga Fink

The real-time, and accurate inference of model parameters is of great importance in many scientific and engineering disciplines that use computational models (such as a digital twin) for the analysis and prediction of complex physical processes. However, f ...

2022

Experimental assessment of an active (acoustic) liner prototype in an acoustic flow duct facility

Hervé Lissek, Maxime Volery, Gaël Matten

In this paper, experimental results of broadband noise reduction in an acoustic flow duct are presented. An active liner composed of an array of electroacoustic absorbers is used. The control law is based on the pressure-based, current driven digital archi ...

SPIE2021

Experimental investigation of sequential narrow impingement channels for turbine cooling

Peter Ott, Michele Gaffuri

Sequentially stacked impingement channels allow for a more effective use of the cooling fluid and can limit the heat transfer reduction due to the crossflow when the number of jets increases. In this paper, sequential impingement channels are experimentall ...

2021

Influence of Large Relative Tip Clearances for a Micro Radial Fan and Design Guidelines for Increased Efficiency

Jan Van Herle, Jürg Alexander Schiffmann, Patrick Hubert Wagner

The blade tip clearance loss was studied experimentally and numerically for a micro radial fan with a tip diameter of 19:2mm. Its relative blade tip clearance, i.e., the clearance dividedby the blade height of 1:82mm, was adjusted with different shims. The ...

2021

Theoretical and Experimental Investigation of a 34 Watt Radial-Inflow Steam Turbine with Partial-Admission

Jan Van Herle, Jürg Alexander Schiffmann, Patrick Hubert Wagner

A micro steam turbine with a tip diameter of 15 mm was designed and experimentally characterized. At the nominal mass flow rate and total-to-total pressure ratio of 2.3 kg/h and 2, respectively, the turbine yields a power of 34 W and a total-to-static isen ...

2021

Theoretical and Experimental Investigation of a 34 Watt Radial-Inflow Steam Turbine with Partial-Admission

Jan Van Herle, Jürg Alexander Schiffmann, Patrick Hubert Wagner

A micro steam turbine with a tip diameter of 15mm was designed and experimentally characterized. At the nominal mass flow rate and total-to-total pressure ratio of 2.3 kgh-1 and 2, respectively, the turbine yields a power of 34W and a total-to-static isent ...

2021

Real-time optimization of load sharing for gas compressors in the presence of uncertainty

Dominique Bonvin, Timm Faulwasser, Alejandro Gabriel Marchetti, Predrag Milosavljevic

This paper investigates the problem of load-sharing optimization of gas compressors in the presence of uncertainty. The objective is to operate a set of compressor units in an energy-efficient way, while at the same time meeting a varying load demand. The ...

ELSEVIER SCI LTD2020

Scale limitations of gas bearing supported turbocompressors for vapor compression cycles

Jürg Alexander Schiffmann

An analysis of single-stage centrifugal compressors supported on dynamic, gas lubricated bearings for driving vapor compression cycles suggests that the maximum feasible compressor power is limited, primarily by the bearing load capacity, in the range from ...

2020

Design and development of the efficient anguilliform swimming robot- MAR

Auke Ijspeert, Peter Eckert, Anouk Looijestijn

Propulsion of swimming robots at the surface and underwater is largely dominated by rotary propellers due to high thrust, but at the cost of low efficiency. Due to their inherently high speed turning motion, sharp propeller blades and generated noise, they ...

2020

Theoretical and Experimental Investigation of a Small-scale, High-speed, and Oil-free Radial Anode Off-gas Recirculation Fan for Solid Oxide Fuel Cell Systems

Jan Van Herle, Jürg Alexander Schiffmann, Patrick Hubert Wagner

The Laboratory for Applied Mechanical Design (LAMD) designed, manufactured, and experimentally tested a novel recirculation fan for a 10 kWe solid oxide fuel cell (SOFC). The fan uses oil-free bearings, more specifically herringbone-grooved journal and spi ...

2020

Dynamic stall on an airfoil undergoing VAWT blade angle of attack variations

Karen Ann J Mulleners, Sébastien Le Fouest, Sabrina Henne

Vertical axis wind turbines have several attractive features in the context of energy production in urban areas, but the inherent aerodynamic complexity of the flow around them has challenged their development on a larger scale. They generally operate at l ...

2020