Article
Physics, Particles & Fields
P. Leon, C. Las Heras
Summary: In this work, the complexity factor of spherically symmetric static distribution is analyzed through the gravitational decoupling method. Both spatial and temporal deformations of the metric function are considered, and conditions are imposed on the complexity factor to close the system of equations. It is found that regularity at the center of the seed and final solutions restrict the deformation of the spatial metric components, particularly in the MGD method. Furthermore, the study shows that solutions with the same temporal components lead to solutions with vanishing complexity factor in the MGD approach. Realistic models are then constructed using different seed solutions such as Tolman IV and FS (Finch-Skeas).
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Mathematics
Frank Merle, Pierre Raphael, Igor Rodnianski, Jeremie Szeftel
Summary: This paper investigates strong singularity formation in compressible fluids, focusing on the compressible three-dimensional Navier-Stokes and Euler equations. By constructing a set of finite energy smooth initial data satisfying suitable barotropic laws, the paper describes in detail the formation of singularity where the corresponding solutions implode at a later time at a point with infinite density. The existence of C-infinity smooth self-similar solutions to the compressible Euler equations, specifically those with quantized values of the speed, plays a crucial role in the proof. The obtained blow up dynamics for the Navier-Stokes problem are all of type II, which are non self-similar.
ANNALS OF MATHEMATICS
(2022)
Article
Meteorology & Atmospheric Sciences
Justin M. Brown, William Dewar, Timour Radko
Summary: In this study, a pseudo-spectral algorithm is introduced to simulate nearly incompressible fluids. A semi-implicit scheme is used to model acoustic waves and evolve the system efficiently. The convergence properties of the numerical code are demonstrated for different cases. The results are compared with the Boussinesq framework to assess the representation of energy exchange. A specific application of salt finger development is included, showing similar energetic behavior to canonical development for oceanographic parameters. However, for more compressible systems, even low-Mach number flows, the results change substantially.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Mathematics, Applied
Jianwei Yang, Xiao Yang, Jianqin Yang, Qihong Shi
Summary: This paper considers the low Mach number limit problem for the compressible viscous micropolar fluid model using the concept of dissipative measure-valued solutions. The research shows that the dissipative measure-valued solutions of the compressible micropolar fluid model converge to the smooth solution of the incompressible micropolar system when the Mach number tends to zero, provided that the initial data is well-prepared.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Computer Science, Software Engineering
Yadi Cao, Yunuo Chen, Minchen Li, Yin Yang, Xinxin Zhang, Mridul Aanjaneya, Chenfanfu Jiang
Summary: This study presents a new method for modeling the interaction between compressible flow, shock waves, and deformable structures. The method can capture shock wave propagation, temperature/density-induced buoyancy effects, and changes in the topology of solids.
ACM TRANSACTIONS ON GRAPHICS
(2022)
Article
Mathematics, Applied
Xumin Gu, Yu Mei
Summary: This article investigates the free boundary problem of compressible isentropic neo-Hookean viscoelastic fluid equations with surface tension. By studying the regularity of classical solutions to the viscoelastic fluid equations in Sobolev spaces, we find that these solutions are uniform in viscosity, and justify the corresponding vanishing viscosity limits. The research results indicate that there is no boundary layer in the free boundary problem of compressible viscoelastic fluids.
SCIENCE CHINA-MATHEMATICS
(2023)
Article
Astronomy & Astrophysics
Ning-Chen Sun, Justyn R. Maund, Paul A. Crowther, Ryosuke Hirai, Amir Kashapov, Ji-Feng Liu, Liang-Duan Liu, Emmanouil Zapartas
Summary: The study found that SN 2019yvr is the second Type Ib supernova with a possible direct detection of its progenitor. However, the spectral energy distribution of the pre-explosion source does not match the expected helium-star progenitor. The study also discovered three episodes of star formation in the SN environment, with a low ejecta mass indicating that the SN progenitor most likely comes from the oldest population. Additionally, the study suggests that SN 2019yvr could possibly be the first Type Ib/c SN for which the progenitor's binary companion is directly detected on pre-explosion images.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Computer Science, Software Engineering
Andrea Giuffre, Matteo Pini
Summary: The article discusses the differences between non-ideal compressible flows and ideal gases, and introduces a software tool called NiceProp for learning and analyzing non-ideal compressible fluid dynamics. The software is aimed at students, researchers, and industry professionals interested in understanding and studying non-ideal compressible flow phenomena.
Article
Mathematics, Applied
Milan Pokorny, Maja Szlenk
Summary: We investigate the existence of weak solutions for a system of partial differential equations that models the behavior of a compressible non-Newtonian fluid at low Reynolds numbers. Despite the lack of L∞ estimate on the velocity divergence, we are able to construct these weak solutions. By combining the regularity theory for singular operators with a logarithmic integral inequality for BMO functions, we adapt the method from Feireisl et al. (2015) to accommodate more relaxed conditions on the velocity.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Mathematics, Applied
Hui Fang, Yihan Fan, Yanping Zhou
Summary: In this paper, the problem of energy equality in the two and three dimensional compressible Navier-Stokes-Korteweg equations with general pressure law is investigated. By using commutator estimation to handle the nonlinear terms, the sufficient conditions for the regularity of weak solutions to conserve energy are obtained.
Article
Astronomy & Astrophysics
Andrea Antoni, Eliot Quataert
Summary: When the collapse of a massive red or yellow supergiant does not result in an energetic supernova, the infall of the convective hydrogen envelope towards the black hole formed from the collapsing core can lead to nearly complete envelope ejection in an explosion. This explosion would show a characteristic red plateau in its light curve and could be similar to luminous red novae with red or yellow supergiant progenitors. The mechanism studied here produces more energetic explosions than the weak shock generated from radiation of neutrino energy.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Physics, Multidisciplinary
A. Amorese, B. Leedahl, M. Sundermann, H. Gretarsson, Z. Hu, H-J Lin, C. T. Chen, M. Schmidt, H. Borrmann, Yu Grin, A. Severing, M. W. Haverkort, L. H. Tjeng
Summary: Nonresonant inelastic X-ray scattering involving an s core level is a powerful spectroscopic method that can characterize the excited states of transition metal compounds. The spherical charge distribution of the s core hole allows for orientation-dependent intensities of spectral features, aiding in the identification of orbital character. The analysis of spectra can be done using well-established Sugano-Tanabe-Kamimura diagrams without adding extra orbital angular momentum components.
Article
Astronomy & Astrophysics
Andrea Antoni, Eliot Quataert
Summary: This study simulates the convection and collapse of red supergiants and finds that the failed explosions of these stars can lead to the formation of rotationally supported flows, which can drive outflows to large radii and produce observable transients.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
M. R. Magee, J. H. Gillanders, K. Maguire, S. A. Sim, F. P. Callan
Summary: Investigations suggest that the ejecta of some Type Iax supernovae (SNe Iax) may be layered to some degree. However, toy models show that heavily mixed models can produce good agreement with SN 2012Z, which has a suggested layered structure. Differences in line profile shapes may be due to blending or stratification. Based on analysis, there is insufficient evidence to suggest that the ejecta of SNe Iax must be layered.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Mathematics, Applied
Jianwei Dong
Summary: This note presents an exact solution for the semi-stationary compressible Stokes problem in R-N, specifically obtaining a velocity form for radial symmetry. The properties of the exact solution are further analyzed.
RICERCHE DI MATEMATICA
(2022)
Article
Thermodynamics
Colette Nicoli, Pierre Haldenwang, Bruno Denet
COMBUSTION SCIENCE AND TECHNOLOGY
(2019)
Article
Thermodynamics
Elias Al Sarraf, Christophe Almarcha, Joel Quinard, Basile Radisson, Bruno Denet
FLOW TURBULENCE AND COMBUSTION
(2018)
Article
Mechanics
Paul Clavin, Bruno Denet
JOURNAL OF FLUID MECHANICS
(2018)
Article
Thermodynamics
Elias Al Sarraf, Christophe Almarcha, Joel Quinard, Basile Radisson, Bruno Denet, Pedro Garcia-Ybarra
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2019)
Article
Physics, Condensed Matter
Pierre-Henri Chavanis, Bruno Denet, Martine Le Berre, Yves Pomeau
EUROPEAN PHYSICAL JOURNAL B
(2019)
Article
Mechanics
Paul Clavin, Bruno Denet
JOURNAL OF FLUID MECHANICS
(2020)
Article
Mechanics
B. Radisson, B. Denet, C. Almarcha
JOURNAL OF FLUID MECHANICS
(2020)
Article
Mechanics
Paul Clavin, Raul Hernandez Sanchez, Bruno Denet
Summary: The critical dynamics of supersonic combustion waves in the context of direct initiation of detonation in a spherical geometry are studied through an asymptotic analysis. Analysis includes factors such as unsteadiness, curvature, and the gradient of the burnt-gas flow. The phenomenon is explained by the dynamics of the sonic point inside the inert rarefaction wave behind the reaction zone, with a critical slowdown leading to detonation failure if the rate of decay is too strong. Successful detonation initiation involves understanding the trajectories in both fully unsteady problems and self-similar CJ solutions in the long-time limit.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Thermodynamics
Karthik Bhairapurada, Bruno Denet, Pierre Boivin
Summary: This study presents possibly the first use of lattice-Boltzmann numerical simulations to investigate thermo-acoustic instabilities of premixed flames. The study examines the interaction between flames and an imposed acoustic field, observing the effects of parametric instability on flames and the influence of the acoustic forcing on plane flames. It also explores self-induced thermo-acoustic oscillations of flames propagating in narrow channels, revealing an unexpected dependency on channel width. The results confirm the capability of the lattice-Boltzmann method to capture the complex coupling between flame dynamics and acoustics.
COMBUSTION AND FLAME
(2022)
Article
Physics, Fluids & Plasmas
Basile Radisson, Bruno Denet, Christophe Almarcha
Summary: The parametric forcing of premixed flames in a Hele-Shaw burner is studied using a vibroacoustic coupling. The thresholds of parametric flattening and instability are observed and compared to a low-frequency theory. The results suggest that the dependency of the parametric threshold on equivalence ratio is lower than predicted, indicating a frequency-dependent Markstein length and an independent flattening threshold in agreement with the Bychkov limit.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Physics, Fluids & Plasmas
Basile Radisson, Bruno Denet, Christophe Almarcha
Summary: This study investigates the influence of gravity and heat loss on the dynamics of flames, finding that stabilizing effects may lead to the creation of new cells and observed patterns. It also offers an explanation for statistical anomalies in the topology of flame fronts.
Article
Thermodynamics
Muhammad Tayyab, Basile Radisson, Christophe Almarcha, Bruno Denet, Pierre Boivin
COMBUSTION AND FLAME
(2020)
Article
Physics, Multidisciplinary
Pierre-Henri Chavanis, Bruno Denet, Martine Le Berre, Yves Pomeau
Article
Physics, Fluids & Plasmas
C. Almarcha, B. Radisson, E. Al Sarraf, E. Villermaux, B. Denet, J. Quinard
Article
Mechanics
Romain Thimothee, Christian Chauveau, Fabien Halter, Colette Nicoli, Pierre Haldenwang, Bruno Denet
COMPTES RENDUS MECANIQUE
(2017)