Concept

Four-velocity

Related publications (113)

Gyrokinetic moment-based simulations of the Dimits shift

Paolo Ricci, Baptiste Jimmy Frei, Antoine Cyril David Hoffmann

We present a convergence study of the gyromoment (GM) approach, which is based on projecting the gyrokinetic distribution function onto a Hermite–Laguerre polynomial basis, focused on the cyclone base case (CBC) (Lin et al., Phys. Rev. Lett., vol. 83, no. ...

2023

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

Anita Frank

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

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

Karen Ann J Mulleners

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 ...

2022

Flow pattern observations and flow pattern map for adiabatic two-phase flow of carbon dioxide in vertical upward and downward direction

Jürg Alexander Schiffmann, Rémi Revellin, David Schmid

A test facility to investigate flow pattern transitions of vertical two-phase flow of CO2 has been built within the scope of the high-luminosity detector upgrades at the European Organization for Nuclear Research (CERN). Adiabatic flow pattern observations ...

2022

Heat transfer of flow boiling carbon dioxide in vertical upward direction

Jürg Alexander Schiffmann, Rémi Revellin, David Schmid

Heat transfer measurements of flow boiling Carbon Dioxide (CO2) in vertical upward direction have been carried out with a dedicated test facility at the European Organization for Nuclear Research (CERN). The experiments have been conducted in a vertical up ...

2022

Device for measuring instantaneous sprint velocity

Kamiar Aminian, Salil Apte, Farzin Dadashi, Benoît Mariani

The invention concerns a device for measuring instantaneous sprint velocity, said device consisting of at least one position and/or one velocity sensor and one IMU sensor that respectively provide position and/or velocity and acceleration signals and where ...

2021

Micromechanical Modelling of Elastic Wave Velocity Variations for Intact Brittle Rocks

Antoine Guggisberg

Until now, the micromechanical wing crack model of Ashby & Sammis 1990 describing the brittle field of rocks has only been used for failure predictions. However, it gives relevant information regarding the crack opening process, so this model is extended t ...

2021

One-minute average cruise track and ship velocity of the Antarctic Circumnavigation Expedition (ACE) undertaken during the austral summer of 2016/2017.

Julia Schmale, Jenny Thomas, Sebastian Johannes Heinz-Josef Landwehr

Dataset abstract The ship's cruise track, velocity, course over ground and heading at one-minute resolution for all five legs of the Antarctic Circumnavigation Expedition (ACE) are derived from a combination of: - the latitude/longitud ...

2020

Synthesis of grid compliant substitute natural gas from a representative biogas mixture in a hybrid Ni/Ru catalysed reactor

Andreas Züttel, Emanuele Moioli, Marco Calizzi, Robin Tobias Andreas Mutschler, Alexandre Borsay

We demonstrate biogas upgrading towards full CO2 conversion in mild conditions in a three-step reactor system using Ru- and Ni-based catalysts. In each of the three reactor stages, the temperature is carefully controlled, thus optimizing the reaction therm ...

2020

Multirotor UAV-based platform for the measurement of atmospheric turbulence: validation and signature detection of tip vortices of wind turbine blades.

Fernando Porté Agel, Lionel Wilhelm, Fernando Carbajo Fuertes

The present study describes the development of a technique for the measurement of atmospheric turbulence and temperature at a point in space based on the integration of a fast-response multi-hole pressure probe and a thermocouple with an inertial measureme ...

2019

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