Review
Engineering, Aerospace
William J. Devenport, K. Todd Lowe
Summary: This article presents a review of historical and recent developments in the understanding of equilibrium and non-equilibrium turbulent boundary layers at incompressible high-Reynolds number conditions. The review focuses on the mean flow, turbulence stress fields, and instantaneous structure, discussing smooth wall and rough wall boundary layers as well as equilibrium and non-equilibrium two-dimensional flows. It concludes with a detailed discussion of boundary layer development in skewed, three-dimensional flows over smooth walls.
PROGRESS IN AEROSPACE SCIENCES
(2022)
Article
Mechanics
Tal Agranov, Michael E. Cates, Robert L. Jack
Summary: Analyzing the entropy production statistics within a lattice-based model of interacting active particles, a detailed phase diagram with five different phases was uncovered. Additionally, the coexistence of first order and second order nonequilibrium phase transition curves was found at a bias-induced tricritical point.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Mechanics
Cecile Monthus
Summary: This passage describes how boundary-driven non-equilibrium Markov models can be transformed into quantum supersymmetric Hamiltonians with many remarkable properties. It discusses the mapping between boundary-driven dynamics and dual equilibrium dynamics, as well as the large deviations of time-averaged observables.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2023)
Article
Physics, Multidisciplinary
Nahuel Freitas, Gianmaria Falasco, Massimiliano Esposito
Summary: This method provides an effective expression for determining probability distribution away from equilibrium and accurately approximates the rate function through linear response theory at the level of the rate function, applicable to various physical and chemical systems. The approach can be extended to transient probabilities and non-autonomous dynamics, creating a virtual flow in probability space to determine the steady state rate function far from equilibrium.
NEW JOURNAL OF PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
Yann-Edwin Keta, Etienne Fodor, Frederic van Wijland, Michael E. Cates, Robert L. Jack
Summary: We analyzed the collective motion that occurs during rare events in systems of active particles, and discussed the associated dynamical phase transition to collective motion. A finite biasing field is needed to induce spontaneous symmetry breaking, and particle alignment is studied both for a two-particle system and for many-particle systems using an optimal-control representation of the biased dynamics. Additionally, a fluctuating hydrodynamic theory is proposed to capture the emergence of polar order in the biased state.
Article
Mechanics
Matthew Bross, Sven Scharnowski, Christian J. Kaehler
Summary: Studies have shown that in compressible turbulent boundary layer flows, the frequencies of superstructures have slightly longer streamwise wavelengths, and there is a distinct increase in the spanwise spacing of superstructures in supersonic cases compared to subsonic and transonic turbulent boundary layers.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Thermodynamics
Agata Czernuszewicz, Lucas Griffith, Alexander Scott, Julie Slaughter, Vitalij Pecharsky
Summary: This study embeds an active NiTi layer into a polymer support structure, enabling stable operation of elastocaloric material in compression state, offering potential for application in regenerative cooling systems.
APPLIED THERMAL ENGINEERING
(2021)
Article
Chemistry, Physical
S. Arman Ghaffarizadeh, Gerald J. Wang
Summary: Through molecular dynamics simulations, we studied a model active-matter system and discovered a range of interesting transport phenomena. By adapting existing results, we established a new relationship in active systems that connects transport and structure, providing a promising step towards predictive and generalizable models.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Mathematics
Leonid A. Bunimovich, Yaofeng Su
Summary: This paper proves a large deviation principle of maximal-type for dynamical systems with arbitrarily slow polynomial mixing rates. Several applications, especially for billiard systems, are also presented.
ADVANCES IN MATHEMATICS
(2023)
Article
Physics, Fluids & Plasmas
Naftali R. Smith
Summary: This study investigates the large deviations in series of finite lengths generated by chaotic maps. The rate functions for the doubling, tent, and logistic maps are analytically obtained, while the rate function of the cat map is determined numerically, revealing strong evidence of a remarkable singularity. Furthermore, a numerical tool for simulating atypical realizations of sequences is developed.
Article
Mechanics
D. D. Wangsawijaya, N. Hutchins
Summary: This study examines the turbulent boundary layers developing over surfaces with spanwise heterogeneous roughness. It finds that the heterogeneous cases induce counter-rotating secondary flows, which are compared to the large-scale turbulent structures over smooth walls. The results suggest that the secondary flows are spanwise-locked turbulent structures, with the strength of the structures and locking efficacy determined by the roughness half-wavelength. The study also finds that the secondary flows exhibit maximum unsteadiness when the roughness half-wavelength is approximately 1.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Naftali R. Smith, Satya N. Majumdar
Summary: This paper investigates the fluctuations of the area A(t) with Hurst exponent H > 0 (e.g., standard or fractional Brownian motion, or the random acceleration process). It is found that in the long-time limit, the distribution of A(t) takes on a non-Gaussian form with different anomalous scaling.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Mechanics
D. Passiatore, L. Sciacovelli, P. Cinnella, G. Pascazio
Summary: This study presents an analysis of a hypersonic turbulent boundary layer with a cooled wall using numerical simulations. The results reveal the occurrence of thermal and chemical non-equilibrium phenomena due to the conversion of kinetic energy to internal energy. Turbulent mixing plays a crucial role in sustaining the thermal non-equilibrium.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Multidisciplinary Sciences
Falko Schmidt, Hana Sipova-Jungova, Mikael Kaell, Alois Wuerger, Giovanni Volpe
Summary: Active nanoparticles in a critical solution show behavior far from equilibrium, with fast orbital rotations observed around the beam axis even with an increase in effective temperature.
NATURE COMMUNICATIONS
(2021)
Article
Astronomy & Astrophysics
Timothy Cohen, Daniel Green, Akhil Premkumar
Summary: Fluctuations in cosmology are crucial and can be coarse grained with Gaussian distribution or dominated by rare fluctuations. The large deviation principle is proposed to diagnose when the fundamental description is necessary. The Fokker-Planck equation governing stochastic inflation shows central limit-type behavior for typical fluctuations, but instantonlike saddle points accompanied by a new energy scale determine fluctuations in the regime of the large deviation principle.
Article
Mathematics, Applied
Freddy Bouchet, Eric Woillez
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2020)
Article
Mechanics
Robert L. Jack, Takahiro Nemoto, Vivien Lecomte
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2020)
Article
Physics, Multidisciplinary
Eric Woillez, Yariv Kafri, Nir S. Gov
PHYSICAL REVIEW LETTERS
(2020)
Article
Physics, Multidisciplinary
Eric Woillez, Freddy Bouchet
PHYSICAL REVIEW LETTERS
(2020)
Article
Mechanics
Nicolas Tizon-Escamilla, Vivien Lecomte, Eric Bertin
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2020)
Article
Physics, Multidisciplinary
Matthieu Vanicat, Eric Bertin, Vivien Lecomte, Eric Ragoucy
Summary: This study investigates the non-trivial correspondence between activity and current in the Asymmetric Simple Exclusion Process (ASEP), applying a similarity transform on the deformed Markov matrix to establish a mapping between two ASEPs with different parameters. The mapping is expressed in the language of Macroscopic Fluctuation Theory (MFT) in the diffusive scaling limit, revealing a regime of Kardar-Parisi-Zhang in the distribution of activity in the SSEP. Additionally, the study characterizes hyperuniformity in particle configurations at large activity and formulates a conjecture for a correlation function in spin chains based on the MFT results.
Article
Mechanics
Tal Agranov, Sunghan Ro, Yariv Kafri, Vivien Lecomte
Summary: By extending recent results on hydrodynamics of diffusive active particles displaying motility-induced phase separation, it was found that the system develops two macroscopic length scales, one related to diffusive length and the other related to collective behavior. The critical behavior of the model belongs to the universality class of a mean-field Ising model in one dimension, with divergence of the latter length scale near the critical point. Additionally, comparison with the ABC model shows differences in the density large deviation function, indicating finite macroscopic extent dictated by the diverging correlation length.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)
Article
Instruments & Instrumentation
Eric Woillez, Jerome Valentin, Philippe-E. Roche
Summary: An analytical model of open-cavity second sound resonators is proposed and validated. The model takes into account diffraction, geometrical misalignments, and flow through the cavity. It is found that resonators can be optimized to selectively sense either the quantum vortex density or the mean velocity of the throughflow.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Physics, Multidisciplinary
Eric Woillez, Jerome Valentin, Philippe-E Roche
Summary: In this study, the density fluctuations of quantum vortex lines were measured in a turbulent flow of superfluid He at different temperatures corresponding to various superfluid fractions. It was found that all vortex power spectra collapse on a single master curve, regardless of the superfluid fraction and mean velocity. The probability distributions of vortex density were observed to be strongly skewed, similar to vorticity distributions in classical turbulence.
Article
Physics, Fluids & Plasmas
Bastien Marguet, Elisabeth Agoritsas, Leonie Canet, Vivien Lecomte
Summary: This paper discusses the super symmetry theory of reversible and irreversible dynamics, as well as its application in fluctuation-dissipation relations.
Article
Materials Science, Multidisciplinary
Nirvana Caballero, Elisabeth Agoritsas, Vivien Lecomte, Thierry Giamarchi
Article
Physics, Fluids & Plasmas
Victor H. Purrello, Jose L. Iguain, Vivien Lecomte, Alejandro B. Kolton
Article
Physics, Fluids & Plasmas
Ydan Ben Dor, Eric Woillez, Yariv Kafri, Mehran Kardar, Alexandre P. Solon