Publications associées à Hypersonique

Three-dimensional micro-CT images of UV-frozen flow fronts recorded at different flow regimes

Véronique Michaud, Jacobus Gerardus Rudolph Staal

Segmented micro-CT images of flow fronts produced by UV-flow freezing. Front morphologies correspond to capilary-dominated, equilibrated and viscous-dominated flow regimes. ...

Zenodo2023

Measurement and modelling of dynamic fluid saturation in carbon reinforcements

Véronique Michaud, Baris Çaglar, Helena Luisa Teixido Pedarros, Guillaume Clément Broggi

We propose a methodology to monitor the progressive saturation of a non-translucent unidirectional carbon fabric stack through its thickness by means of X-ray radiography and extract the dynamic saturation curves using image analysis. Four constant flow ra ...

2023

Formation of the cavity on a planar interface subjected to a perturbed shock wave

Naifu Peng, Ho Ling Li, Yue Yang

We report the mechanism and modeling for the formation of cavitylike structures on a planar interface subjected to a perturbed shock wave. The cavity is distinguished from bubbles and spikes formed in the standard Richtmyer-Meshkov instability (RMI). The t ...

AMER PHYSICAL SOC2023

An experimental and analytical study of wind turbine wakes under pressure gradient

Fernando Porté Agel, Arslan Salim Dar, Abraham Starbuck Gertler

This work is dedicated to the systematic investigation of wind turbine wakes under the effect of pressure gradients. Wind tunnel experiments are carried out with a wind turbine positioned on straight ramps of increasing angle such that it experiences an ap ...

2023

Numerical and experimental investigation of spiral-grooved gas journal bearings

Elia Iseli

Small-scale turbomachinery is increasingly used in carbon-free energy conversion systems, such as commercial or domestic scale heat pumps, fuels cells for transportation and waste heat recovery. The usage of aerodynamic bearings allows the design of compac ...

EPFL2022

Fourier Collocation and Reduced Basis Methods for Fast Modeling of Compressible Flows

Jan Sickmann Hesthaven, Deep Ray

A projection-based reduced order model (ROM) based on the Fourier collocation method is proposed for compressible flows. The incorporation of localized artificial viscosity model and filtering is pursued to enhance the robustness and accuracy of the ROM fo ...

GLOBAL SCIENCE PRESS2022

Model order reduction for compressible flows solved using the discontinuous Galerkin methods

Jan Sickmann Hesthaven

Projection-based reduced order models (ROM) based on the weak form and the strong form of the discontinuous Galerkin (DG) method are proposed and compared for shock-dominated problems. The incorporation of dissipation components of DG in a consistent manne ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

Femtosecond laser-shockwave induced densification in fused silica

Yves Bellouard, Pieter Vlugter, Arunkrishnan Radhakrishnan, Julien Gilles Edgar Gateau

A tightly focused femtosecond laser-beam in the non-ablative regime can induce a shockwave sufficiently intense to reach local pressures in the giga-Pascal range or more. In a single beam configuration, the location of the highest-pressure zone is nested w ...

2022

Transport barrier in 5D gyrokinetic flux-driven simulations

Two ways for producing a transport barrier through strong shear of the E x B poloidal flow have been investigated using GYSELA gyrokinetic simulations in a flux-driven regime. The first one uses an external poloidal momentum (i.e. vorticity) source that lo ...

IOP Publishing Ltd2022

Experimental investigation of surface roughness effect on a free-flight sphere in a Ludwieg tube

Seong-Hyeon Park

Understanding the aerodynamic coefficients of meteoroid fragments, deorbiting space debris, or launch vehicle stages through atmospheric reentry is essential for ground risk assessments. In high enthalpy flow, surface roughness is a crucial factor affectin ...

KOREAN SOC MECHANICAL ENGINEERS2022