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Nicolas Bonne

Publications and source records attributed to Nicolas Bonne.

5 recordsLinked to original sources

Engine position effects on contrail evolution for a realistic aircraft configuration

This study investigates the influence of representative engine positions on contrail evolution during the vortex and dissipation regimes, using three-dimensional simulations of a realistic aircraft geometry. Large Eddy Simulations are employed, coupled with an Eulerian microphysical bulk model, and initialized using fields obtained from prior Reynolds-Averaged Navier-Stokes simulations. This approach enables a consistent transition from near-field jet-vortex interactions to far-field wake dynamics. Three engine placements are examined under two atmospheric stratifications and two relative humidity conditions. The results reveal that engine position influences the onset and evolution of vortex instabilities, alters the descent of the vortex pair, and leads to slight changes in the distribution of particles within the wake. Despite these aerodynamic differences, the microphysical properties of the contrails tend to converge over time for the parameters and configurations covered in this study. From a broader perspective, engine placement strongly influences initial contrail formation and early vortex-regime dynamics. At later stages, these differences largely disappear, as vortex dynamics and atmospheric conditions dominate over the initial dilution changes induced by engine position.

physics.flu-dyn

Numerical investigation of engine position effects on contrail formation and evolution in the near-field of a realistic aircraft configuration

The present study investigates the impact of engine position on contrail formation and near-field evolution in a realistic three-dimensional aircraft configuration. Detailed numerical simulations are conducted using a Reynolds-Averaged Navier-Stokes (RANS) approach coupled with mesh adaptation techniques. A Eulerian microphysical model is used to characterize contrail ice crystal properties and their evolution under varying dilution conditions. The setup is based on a Boeing 777-like geometry, including fuselage, wings, engines, and tailplane. Two microphysical activation scenarios are considered: one incorporating adsorption-based ice nucleation and the other assuming fully activated soot particles. The latter for two soot number emission indices. The dilution process and wake structure exhibit a strong dependence on engine placement, which significantly influences plume saturation. In highly diluted configurations, enhanced early-stage mixing reduces plume temperature and increases relative humidity, favoring the growth of larger ice crystals. Depending on the soot number concentration, vapor depletion effects may outweigh dilution-driven changes in water vapor availability. In adsorption-limited activation scenarios, increased dilution reduces the concentration of sulfur species, leading to a lower activation fraction and the formation of smaller ice crystals. Additionally, across the scenarios, the modified jet-vortex interaction alters particle distribution and their access to water vapor, further shaping their growth. These effects ultimately impact the contrail's optical properties, particularly its optical thickness.

physics.flu-dyn

STRAUSS: Sonification Tools & Resources for Analysis Using Sound Synthesis

Sonification, or conveying data using non-verbal audio, is a relatively niche but growing approach for presenting data across multiple specialist domains including astronomy, climate science, and beyond. The STRAUSS Python package aims to provide such a tool, which builds upon previous approaches to provide a powerful means to explore different ways of expressing data, with fine control over the output audio and its format. STRAUSS is a free, open source (FOSS) package, designed to allow flexible and effective sonification to be integrated into data workflows, in analogy to widely used visualisation packages. The remit of STRAUSS is broad; it is intended to be able to bridge between ad-hoc solutions for sonifying very particular datasets, and highly technical compositional and sound-design tools that are not optimised for sonification, or may have a steep learning curve. The code offers a range of approaches to sonification for a variety of contexts (e.g. science education, science communication, technical data analysis, etc). To this end, STRAUSS is packaged with a number of examples of different sonification approaches, and preset configurations to support "low-barrier, high-ceiling" approach. STRAUSS has been used to produce both educational resources and analysis tools.

astro-ph.IM

Communicating the gravitational-wave discoveries of the LIGO-Virgo-KAGRA Collaboration

The LIGO-Virgo-KAGRA (LVK) Collaboration has made breakthrough discoveries in gravitational-wave astronomy, a new field that provides a different means of observing our Universe. Gravitational-wave discoveries are possible thanks to the work of thousands of people from across the globe working together. In this article, we discuss the range of engagement activities used to communicate LVK gravitational-wave discoveries and the stories of the people behind the science, using the activities surrounding the release of the third Gravitational-Wave Transient Catalog as a case study.

astro-ph.IM

Reproducing the Higgs boson data with vector-like quarks

Vector-Like (VL) quarks arise in the main alternatives to the supersymmetric extensions of the Standard Model (SM). Given the experimental possibility of a 125 GeV Higgs boson with rates significantly different from the SM expectations, it is motivating to study the effects of VL quarks on the Higgs boson cross sections and branching ratios. We perform a systematic search for the minimal field contents and gauge group representations of VL quarks able to significantly improve the fit of the measured Higgs rates, and simultaneously, to satisfy the direct constraints on VL quark masses as well as the electro-weak precision tests. In particular, large enhancements can be achieved in certain diphoton channels - as pointed out by both the ATLAS and CMS Collaborations - optimizing then the Higgs rate fit. This is a consequence of the introduction of VL quarks, with high electric charges of 8/3 or -7/3, which are exchanged in the Higgs-to-diphoton loop. Interestingly, the field contents and formal Higgs couplings obtained here are similar to those of scenarios in warped/composite frameworks arising from different motivations. The various exotic-charge quarks predicted, possibly below the TeV scale, might lead to a rich phenomenology soon at the LHC.

hep-ph