Publications associées à Aile delta

The effects of kinematics, flexibility, and planform on the vortex formation and aerodynamic performance of flapping wing flight

In this thesis, the aerodynamic challenges in flapping wing flight are addressed. In particular, the effects of different wing kinematics, flexibilities, and planforms on the the leading edge vortex development and aerodynamic performance are investigated. ...

EPFL2023

Experimental quantification of unsteady leading-edge flow separation

Karen Ann J Mulleners, Julien Dominique Claude Deparday

We propose here a method to experimentally quantify unsteady leading-edge flow separation on aerofoils with finite thickness. The methodology relies on the computation of a leading-edge suction parameter based on measured values of the partial circulation ...

Cambridge University Press2022

Flying in Private Mode: Understanding and Improving the Privacy ICAO Address Program

Guillaume Michel Le Bars

Location privacy of aircraft has recently gained attention as air traffic management was modernized using novel surveillance technologies. Business aviation circles and various military and government entities voiced serious concerns about automated and ub ...

AMER INST AERONAUTICS ASTRONAUTICS2021

Crack front waves: A 3D dynamic response to a local perturbation of tensile and shear cracks

Jean-François Molinari, Fabian Barras, Damien Spielmann, Fatima-Ezzahra Fekak

Crack front waves are long-lived perturbations propagating along the crack front. They are triggered by heterogeneities on the crack plane, as for instance tough asperities, which disturb the crack front shape. Crack front waves are thought to leave a trac ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Suppressing tip-leakage vortex cavitation by overhanging grooves

Mohamed Farhat, Huaiyu Cheng

In the present paper, a new control method for tip-leakage vortex (TLV) cavitation is proposed. This method, which combines the effects of grooves and winglets, is made of overhanging grooves (OHGs) fitted at the tip of a hydrofoil. Experimental and numeri ...

SPRINGER2020

A bioinspired Separated Flow wing provides turbulence resilience and aerodynamic efficiency for miniature drones

Stefano Mintchev, Matteo Di Luca

Small-scale drones have enough sensing and computing power to find use across a growing number of applications. However, flying in the low-Reynolds number regime remains challenging. High sensitivity to atmospheric turbulence compromises vehicle stability ...

AMER ASSOC ADVANCEMENT SCIENCE2020

Distinct transition in flow statistics and vortex dynamics between low- and high-extent turbulent drag reduction in polymer fluids

Tobias Schneider

Flexible polymer additives are known to reduce the energy dissipation and friction drag in turbulent flows. As the fluid elasticity increases, the flow undergoes several stages of transitions. Much attention in the area has been focused on the onset of dra ...

2018

Flow control of weakly non-parallel flows: application to trailing vortices

François Gallaire, Giacomo Valerio Iungo, Francesco Viola, Erica Pezzica

A general formulation is proposed to control the integral amplification factor of harmonic disturbances in weakly non-parallel amplifier flows. The sensitivity of the local spatial stability spectrum to a base-flow modification is first determined, general ...

Cambridge University Press2017

Bioinspired morphing wings for extended flight envelope and roll control of small drones

Dario Floreano, Stefano Mintchev, Flavio Noca, Grégoire Hilaire Marie Heitz, Matteo Di Luca

Small-winged drones can face highly varied aerodynamic requirements, such as high manoeuvrability for flight among obstacles and high wind resistance for constant ground speed against strong headwinds that cannot all be optimally addressed by a single aero ...

Royal Society, The2017

Impact of rotating and fixed nozzles on vortex breakdown in compressible swirling jet flows

François Gallaire, Leonhard Kleiser

Vortex breakdown of swirling, round jet flows is investigated in the compressible, subsonic regime by means of Direct Numerical Simulation (DNS). This is achieved by solving the compressible Navier-Stokes equations on a cylindrical grid using high-order sp ...

Elsevier2016

Mode selection in trailing vortices: harmonic response of the non-parallel Batchelor vortex

François Gallaire, Francesco Viola, Cristobal Manuel Arratia Martinez

In the present study, the response of model trailing vortices subjected to a harmonic forcing is studied. To this purpose, a globally stable non-parallel Batchelor vortex is considered as the baseflow. Direct numerical simulations (DNS) show that a large v ...

Cambridge University Press2016

A method to visualise near wall fluid flow patterns using locally resolved convective heat transfer experiments

Peter Ott, Alexandros Terzis, Bernhard Weigand

The present study demonstrates an alternative approach for describing ﬂuid ﬂow characteristics very close to the wall, using locally resolved convective heat transfer experiments. Heat transfer coefﬁcients on the base surface and around a surface mounted v ...

Elsevier2015

A Comparative Study of the Local Heat Transfer Distributions Around Various Surface Mounted Obstacles

Peter Ott, Alexandros Terzis, Robert Wyssmann, Dirk Ullmer

In many engineering applications, heat transfer enhancement techniques are of vital importance in order to ensure reliable thermal designs of convective heat transfer applications. This study examines experimentally the heat transfer characteristics on the ...

Science Press2014