Article
Mechanics
E. Nadaf, J. M. Brown, T. Radko
Summary: This study investigates the behavior of turbulent wakes generated by a sphere moving at constant speed in a non-uniformly stratified fluid through high-resolution direct numerical simulations. The results show that even small spatial non-uniformities of stratification can have a significant impact on the dynamics, structure, and evolution of wakes. Wakes in non-uniformly stratified fluids are found to be more horizontally spread and exhibit stronger internal waves compared to linear stratification. The persistence period of wakes is shown to increase with increasing Froude number, and the longevity of wakes is reduced in weak local gradients.
Article
Geochemistry & Geophysics
Bo Wu, Li Zhao, Xiaofei Chen
Summary: A novel method for computing the Earth's normal modes, incorporating the Langer approximation into the theory of generalized reflection/transmission coefficients, has been successfully developed to overcome limitations of traditional analysis and produce satisfactory results. Further research is planned to tackle the asymptotic computation of spheroidal modes, particularly those high-frequency trapped modes where current accuracy is inadequate.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Engineering, Marine
Jun Zhang, Zhichong Yao, Fangwen Hong, Genshui Zhou, Debao Gao, Boyue Su
Summary: This study mainly focuses on the effect of internal waves generated by a slender body in a stratified fluid on surface flow, using theoretical calculations and experimental methods. The results analyze wave patterns, the maximum peak-to-peak velocity of surface flow, and its variation with movement parameters.
Article
Mechanics
Binbin Zhao, Tianyu Zhang, Wenyang Duan, Zhan Wang, Xinyu Guo, Masoud Hayatdavoodi, R. Cengiz Ertekin
Summary: The paper applies the MCC-RL model to investigate internal waves generated by a moving body on the bottom. Comparison with Euler's solutions shows good agreement and accuracy of the MCC-RL results. It is found that the amplitudes of the generated internal solitary waves in front of the moving body increase as the body speed exceeds a critical value, and decrease when the speed further increases.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Zhi-chong Yao, Jun Zhang, De-bao Gao, Chuan-qi Liu, Fang-wen Hong
Summary: A surface particle image velocimetry (PIV) technique was developed to measure the surface flow field of internal waves, and successfully applied in laboratory experiments. The experimental results showed good agreement with theoretical predictions, providing important support for further research on the characteristics of internal wave wakes.
JOURNAL OF HYDRODYNAMICS
(2022)
Article
Physics, Fluids & Plasmas
Jan Rombouts, Lendert Gelens
Summary: This paper investigates the factors influencing wave speed in oscillatory media, including the size, frequency, and time-scale separation of pacemaker regions. Analytical tools such as singular perturbation and phase reduction methods are used to analyze two types of negative-feedback oscillators based on bistability and including time delay in the negative feedback. The analytical estimates are compared to numerical simulations previously described in the paper.
Article
Physics, Fluids & Plasmas
Nicolas Lanchon, Daniel Odens Mora, Eduardo Monsalve, Pierre-Philippe Cortet
Summary: We conducted laboratory experiments in a linearly stratified fluid and found that turbulence driven by internal gravity waves can approach statistical homogeneity and axisymmetry. Nonlinearities develop through the establishment of discrete frequencies of internal wave modes when the forcing is increased. We also discovered that the most energetic modes are resonant eigenmodes of the fluid domain. By introducing slightly tilted panels, we were able to inhibit the emergence of discrete wave modes and achieve a turbulent flow with a continuum of energy in the frequency and wave-number domains.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Astronomy & Astrophysics
Daniel Lecoanet, Matteo Cantiello, Evan H. Anders, Eliot Quataert, Louis-Alexandre Couston, Mathieu Bouffard, Benjamin Favier, Michael Le Bars
Summary: Recent photometric observations of massive stars have shown widespread low-frequency 'red noise' variability, interpreted as internal gravity waves (IGWs). Simulations and theoretical calculations have demonstrated discrepancies in predicting the manifestation of IGWs at the surface, with numerical simulations helping to verify the theoretical approach.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Mechanics
Baiyang Song, Huan Ping, Hongbo Zhu, Dai Zhou, Yan Bao, Yong Cao, Zhaolong Han
Summary: In this study, the impact of incoming turbulence on the flow dynamics behind a single main cylinder was investigated using direct numerical simulations. The results showed that the incoming turbulence significantly affected the drag and lift coefficients and accelerated the turbulent transition of shear layers.
Article
Geochemistry & Geophysics
Caiwang Shi, Hengxin Ren, Zhengbo Li, Xiaofei Chen
Summary: This paper proposes a semi-analytical spectral element method (SASEM) to calculate the normal and leaky modes of elastic waves propagating in a stratified model. The method is validated through numerical tests and applied to a vertically inhomogeneous offshore model. The analysis shows differences between leaky modes and normal modes due to the increasing wavefields in the half-space. The effective calculation of leaky modes allows for constraining the P-wave velocity using leaky-mode dispersion curves.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Mechanics
C. J. Lloyd, R. M. Dorrell, C. P. Caulfield
Summary: A simulation of stably stratified plane Poiseuille flow at moderate Reynolds and Richardson numbers reveals the dynamics described as a series of internal waves with linear dispersion relationship in the channel core. The visualizations show the presence of hairpin vortices dominating the outer region and being different from the ones observed in unstratified boundary layer flows. Outer region ejection events induced by high amplitude waves transport the hairpin vortices into the channel core, generating high-amplitude internal waves, high dissipation, and wave breaking.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Astronomy & Astrophysics
C. Boocock, D. Tsiklauri
Summary: This paper investigates the nonlinear effects of torsional Alfven wave propagation in the solar corona using magnetohydrodynamic simulations. By deriving the nonlinear governing equations and comparing simulation outputs, it is found that the Alfven wave excites magnetosonic waves and self-interacts through coupling, resulting in the formation of shock waves. These nonlinear effects may lead to enhanced Alfven wave heating beyond phase mixing alone.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
C. Boocock, D. Tsiklauri
Summary: The study focuses on the propagation and phase mixing of torsional Alfven waves in a magnetic field, with a corrected analytical solution and demonstration using the TAWAS code. Parameter study reveals that phase mixing is strongest for high frequency Alfven waves in highly divergent magnetic fields. Comparison between different solvers shows accurate results within the WKB approximation but underestimation of wave damping beyond its limit.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Alharbi, I Ballai, V Fedun, G. Verth
Summary: The study investigates the slow sausage waves in the solar atmosphere using a two-fluid model, focusing on the interaction between charged particles and neutrals. Results show that waves associated with charged particles are affected by gravitational stratification, while waves associated with neutrals are affected by wavelength.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Engineering, Marine
Jin Chai, Zhiying Wang, Zixuan Yang, Zhan Wang
Summary: In this paper, numerically investigation is conducted on the internal wave wakes generated by a submerged moving body in a stratified flow with a pycnocline. The influences of different hydrodynamic parameters on the wakes are systematically analyzed, and scaling laws for the variation of wake angle are found. Furthermore, vortex structures and turbulent kinetic energy distributions in the wakes are explored.
Article
Physics, Mathematical
A. L. Kupershtokh, E. V. Ermanyuk, N. V. Gavrilov
COMMUNICATIONS IN COMPUTATIONAL PHYSICS
(2015)
Article
Physics, Multidisciplinary
C. Brouzet, E. V. Ermanyuk, S. Joubaud, I. Sibgatullin, T. Dauxois
Article
Mechanics
C. Brouzet, I. N. Sibgatullin, H. Scolan, E. V. Ermanyuk, T. Dauxois
JOURNAL OF FLUID MECHANICS
(2016)
Article
Mechanics
C. Brouzet, E. Ermanyuk, S. Joubaud, G. Pillet, T. Dauxois
JOURNAL OF FLUID MECHANICS
(2017)
Article
Physics, Fluids & Plasmas
C. Brouzet, I. N. Sibgatullin, E. V. Ermanyuk, S. Joubaud, T. Dauxois
PHYSICAL REVIEW FLUIDS
(2017)
Article
Thermodynamics
A. A. Chernov, A. A. Pil'nik, M. N. Davydov, E. Ermanyuk, M. A. Pakhomov
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2018)
Article
Mechanics
G. Pillet, E. V. Ermanyuk, L. R. M. Maas, I. N. Sibgatullin, T. Dauxois
JOURNAL OF FLUID MECHANICS
(2018)
Article
Mechanics
N. A. Serdtseva, N. V. Gavrilov, E. V. Ermanyuk
JOURNAL OF APPLIED MECHANICS AND TECHNICAL PHYSICS
(2011)
Article
Mechanics
B. Voisin, E. V. Ermanyuk, J. -B. Flor
JOURNAL OF FLUID MECHANICS
(2011)
Article
Mechanics
P. D. Hicks, E. V. Ermanyuk, N. V. Gavrilov, R. Purvis
JOURNAL OF FLUID MECHANICS
(2012)
Article
Physics, Multidisciplinary
Helene Scolan, Eugeny Ermanyuk, Thierry Dauxois
PHYSICAL REVIEW LETTERS
(2013)
Proceedings Paper
Engineering, Electrical & Electronic
Ilias Sibgatullin, Eugeny Ermanyuk, Xu Xiulin, Leo Maas, Thierry Dauxois
2017 IVANNIKOV ISPRAS OPEN CONFERENCE (ISPRAS)
(2017)
Article
Mechanics
C. Brouzet, E. V. Ermanyuk, M. Moulin, G. Pillet, T. Dauxois
JOURNAL OF FLUID MECHANICS
(2017)
Proceedings Paper
Mechanics
T. Dauxois, C. Brouzet, E. Ermanyuk, S. Joubaud, D. Le Tourneau, I. Sibgatullin
24TH INTERNATIONAL CONGRESS OF THEORETICAL AND APPLIED MECHANICS - FOUNDATION OF MULTIDISCIPLINARY RESEARCH
(2017)
Article
Mechanics
E. V. Ermanyuk, N. D. Shmakova, J-B Flor
JOURNAL OF FLUID MECHANICS
(2017)