Publications associées à Signal velocity

Impact of the turbulence wavenumber spectrum and probing beam geometry on Doppler reflectometry perpendicular velocity measurements

The perpendicular propagation velocity of turbulent density fluctuations is an important parameter in fusion plasmas, since sheared plasma flows are crucial for reducing turbulence, and thus an essential input parameter for turbulent transport simulations. ...

IOP Publishing Ltd2023

Space-time wave packets with reduced divergence and tunable group velocity generated in free space after multi-mode fiber propagation

Tobias Kippenberg, Maxim Karpov, Hao Song, Xinzhou Su

Previously, space-time wave packets (STWPs) have been gen-erated in free space with reduced diffraction and a tunable group velocity by combining multiple frequency comb lines each carrying a single Bessel mode with a unique wave num-ber. It might be poten ...

Optica Publishing Group2023

An elastic rod in frictional contact with a rigid cylinder

Pedro Miguel Nunes Pereira de Almeida Reis, Paul Grandgeorge, Tomohiko Sano

We investigate the load transmission along an elastic rod of finite cross-section in contact with a rigid cylinder, as system often referred to as the generalized capstan problem. In the presence of friction, the idealized classic capstan equation predicts ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Attenuation of Lamb Modes and SH Waves near cut-off Frequencies

Soumya Yandrapalli, Victor Plessky

Near cut-off frequencies, the shear horizontal (SH) and Lamb modes in a platelet are created by a bulk acoustic wave bouncing up and down between the platelet sides in an almost vertical direction. The small inclination angle corresponds to slow drift of e ...

IEEE2020

Instability of a thin viscous film flowing under an inclined substrate: steady patterns

François Gallaire, Gioele Mariano Nicolò Balestra, Pier Giuseppe Ledda, Gaëtan Pierre Clément Lerisson

The flow of a thin film coating the underside of an inclined substrate is studied. We measure experimentally spatial growth rates and compare them to the linear stability analysis of a flat film modelled by the lubrication equation. When forced by a statio ...

Cambridge University Press2020

Particle transport at arbitrary timescales with Poisson-distributed collisions

Ambrogio Fasoli, Ivo Furno, Paolo Ricci, Marcelo Baquero Ruiz, Fabian Manke

We develop a model to investigate the time evolution of the mean location and variance of a random walker subject to Poisson-distributed collisions at constant rate. The collisions are instantaneous velocity changes where a new value of velocity is generat ...

2019

Force measurement of a gas-assisted atomization using an impulse probe

Farzad Vakili Farahani

The main objective of this study was to develop further insight into the mass flux characterization of an effervescent atomization. The spray is injected through an industrial effervescent nozzle, and is measured using a newly developed coupled PDPA + IS m ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Orthogonally polarized frequency comb generation from a Kerr comb via cross-phase modulation

Tobias Kippenberg, Maxim Karpov, Martin Hubert Peter Pfeiffer, Arne Kordts, Lin Zhang

We experimentally demonstrate that a single microresonator can emit two orthogonally polarized individually coherent combs: (i) a strong polarized soliton comb and (ii) an orthogonally polarized continuous wave seeded weaker comb, generated from the first ...

OPTICAL SOC AMER2019

Hydraulic Reconstruction of the 1818 Gietro Glacial Lake Outburst Flood

Christophe Ancey, Tomás Alfredo Trewhela Palacios, Eric Bardou, Martin Funk

In the spring of 1818, ice avalanches from the Gietro Glacier created an ice dam, which in turn formed a glacial lake in the Drance Valley (Canton of Valais, Switzerland). Today, its maximum volume is estimated to have been 25x10(6) m(3). Cantonal authorit ...

2019

Flow field in a reservoir subject to pumped-storage operation - in situ measurement and numerical modeling

Anton Schleiss, Giovanni De Cesare, Michael Müller

In pumped-storage reservoirs, turbulent kinetic energy input from plant operation can be considerably high. Flow velocities were measured by Acoustic Doppler Current Profilers near the intake/outlet structure to describe flow patterns induced by pumped-sto ...

2018