Article
Physics, Multidisciplinary
Moumita Indra, K. K. Ghosh, Saibal Ray
Summary: The study investigates the propagation of fully nonlinear ion acoustic solitary waves in a magneto-plasma with degenerate electrons. The article presents a rigorous and general analytical study based on previous work, confirming the assumption that only hump-shaped waves are possible and the algebraic equation for the maximum density uniquely determines it for humps (assuming N > 1). Additionally, the study analytically confirms the assertion that N decreases with 1x (the direction cosine of the wave vector k along the x-axis) and increases with the Mach number M.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Multidisciplinary Sciences
Kevin Patrick Griffin, Lin Fu, Parviz Moin
Summary: A transformation method mapping compressible wall-bounded turbulent flows to the incompressible law of the wall has been proposed, successfully collapsing numerical simulation data from various flows without specific tuning. The transformation is successful across the entire inner layer of the boundary layer, verifying its performance for compressible wall-bounded flows.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Physics, Fluids & Plasmas
Peng Zhang, Yubin Song, Yilang Liu, Zhenhua Xia
Summary: This study investigates the equivalence of different thermal boundary conditions in compressible turbulent channel flows. The results show that the three thermal boundary conditions have almost negligible effect on the velocity field, whereas some discernible deviations can be observed for the temperature field in the near-wall region.
Article
Mechanics
Mehdi Khalloufi, Jesse Capecelatro
Summary: Particle-resolved simulations were performed to study subsonic and transonic flows past random arrays of spherical particles. A new drag correlation was proposed to describe the behavior of dilute to moderately dense suspensions in subsonic and weakly supersonic flow. The study also found that neighbor-induced aerodynamic interactions have an impact on the critical Mach number and the increase in compressibility effects on drag.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Mathematics, Applied
R. Herbin, J-C Latche, K. Saleh
Summary: This paper investigates the behaviour of staggered discretization based numerical schemes for the barotropic Navier-Stokes equations at low Mach number. It rigorously proves that these schemes are asymptotic preserving and converge to the solutions of incompressible flows as the Mach number approaches zero. Numerical results support the analysis and provide insight into the behavior of the scheme for shock solutions.
MATHEMATICS OF COMPUTATION
(2021)
Article
Mechanics
S. Arun, A. Sameen, Balaji Srinivasan, Sharath S. Girimaji
Summary: This study examines the definition and transport equation of the scale-space energy density function for compressible flows. It first defines the energy density function and then analyzes data from mixing layers to study the scale-space behavior at different Mach numbers. The research shows that production is influenced by long-distance interactions, whereas pressure dilatation effects are more localized.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Jie Yao, Fazle Hussain
Summary: Compressible turbulent plane Couette flows with high Reynolds and Mach numbers were studied through direct numerical simulation. Various turbulence statistics were compared with incompressible flows. The skin friction coefficient decreases with Reynolds number but weakly depends on Mach number. The thermodynamic properties show significant variations with Mach number. Proper scaling transformations collapse the mean velocity profiles for compressible and incompressible cases well. Semilocal units yield a better collapse for Reynolds stress profiles compared to wall units. The length scale of near-wall coherent structures and the strength of the superstructures increase with Reynolds number. The streamwise coherence of the superstructures degrades with increasing Mach number.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Tingting Li, Zhiwen Cui, Xianxu Yuan, Ying Zhang, Qiang Zhou, Lihao Zhao
Summary: In this study, we conducted direct numerical simulations to investigate the behavior of particle suspensions in compressible turbulent vertical channel flows. We found that the compressibility effect amplifies the mean velocity, fluctuations, and slip velocity of particles in the streamwise direction. Additionally, the wall-normal and spanwise fluctuations of particle velocities are augmented by the compressible effect in the channel core region. The quadrant analysis of fluid fluctuation velocities at particle positions revealed preferential distributions in certain quadrants, indicating the influence of compressible flows on particle wall-normal transport.
Article
Mechanics
P-F Yang, J. Fang, L. Fang, A. Pumir, H. Xu
Summary: We derive analytic relations for the second- and third-order moments of the spatial gradient of fluid velocity in compressible turbulence. These relations generalize known relations in incompressible flows and can be approximately applied in a mixing layer. We also discuss the experimental determination of these moments for isotropic compressible turbulence.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Mechanical
Chung-Gang Li, Rahul Bale, WeiHsiang Wang, Makoto Tsubokura
Summary: In this study, a sharp interface immersed boundary method (IBM) for low Mach number viscous compressible flows is developed. The IBM utilizes a robust interpolation scheme to ensure stability for complex geometries with zero-thickness walls. By gradually reducing the order of interpolation near the wall, the method eliminates interaction between opposite sides in high order schemes. It also efficiently handles moving objects in compressible flows without requiring any special treatment. The method has been successfully applied to aerodynamic simulations, compression and expansion processes, and aeroacoustics simulations.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Mechanics
Francesco Tosto, Claudio Lettieri, Matteo Pini, Piero Colonna
Summary: The study of paradigmatic compressible one-dimensional flows provides insights into the loss mechanisms of fluid machinery components in power and propulsion systems. The research shows that in Rayleigh flows, energy is converted, while entropy is generated in Fanno flows due to friction. Molecular complexity and thermodynamic state significantly impact the performance of the working fluid.
Article
Computer Science, Interdisciplinary Applications
Joshua Hope-Collins, Luca di Mare
Summary: This paper reviews the low-Mach behavior of compressible flow schemes by considering both convective and acoustic effects. Three diffusion scalings are identified, and guidelines for the design of low-Mach schemes are refined.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
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
Mechanics
G. Sivaprasad, Gopalapillai Rajesh, T. Jayachandran, Arun Kumar Rajagopal
Summary: This paper investigates the strong shock solutions in a supersonic wedge experimentally, analytically, and numerically. Experiments and computations are conducted on scaled-down models for the two types of shock reflection to be possible. The time-resolved schlieren observation of the flow evolution revealed that the shock formation is a highly dynamic transition of the starting shock from a strong Mach reflection (MR) to a weak regular reflection (RR) via a strong RR reflection over a constant shock wave angle for a wedge angle less than the detachment criterion angle for the shock transition. However, when the wedge angle is greater than the detachment criterion angle, the shock moves over the wedge with the MR structures of diminishing Mach stem height at a constant incident shock wave angle. These intermediate shock reflections are found to be unstable and oscillate at high amplitude and low frequencies to upstream pressure fluctuations. The nature of the intermediate shock reflection during the shock transition over the wedge has also been studied using an unsteady second-order two-dimensional compressible Navier-Stokes solver code with shear stress transport k-epsilon turbulence modeling. The computed flow parameters around the intermediate shock reflections confirmed that these are indeed strong shock reflections believed to be unphysical in steady wedge flows.
Article
Mathematics, Applied
Nader Masmoudi, Frederic Rousset, Changzhen Sun
Summary: In this study, we establish uniform regularity estimates for the isentropic compressible Navier-Stokes system in smooth domains with Navier slip condition on the boundary, considering the general case of ill-prepared initial data. By considering the boundary layer effects and the ill-prepared initial data assumption, we prove uniform estimates in an anisotropic functional framework with only one normal derivative close to the boundary. This allows us to demonstrate the local existence of a strong solution independent of the Mach number and to justify the incompressible limit using a simple compactness argument.
JOURNAL DE MATHEMATIQUES PURES ET APPLIQUEES
(2022)
Review
Astronomy & Astrophysics
A. Greco, W. H. Matthaeus, S. Perri, K. T. Osman, S. Servidio, M. Wan, P. Dmitruk
SPACE SCIENCE REVIEWS
(2018)
Article
Physics, Fluids & Plasmas
N. Andres, F. Sahraoui, S. Galtier, L. Z. Hadid, P. Dmitruk, P. D. Mininni
JOURNAL OF PLASMA PHYSICS
(2018)
Article
Physics, Fluids & Plasmas
C. A. Gonzalez, T. N. Parashar, D. Gomez, W. H. Matthaeus, P. Dmitruk
PHYSICS OF PLASMAS
(2019)
Article
Physics, Fluids & Plasmas
M. Fontana, P. D. Mininni, P. Dmitruk
PHYSICAL REVIEW FLUIDS
(2018)
Article
Physics, Fluids & Plasmas
R. Lugones, P. Dmitruk, P. D. Mininni, A. Pouquet, W. H. Matthaeus
PHYSICS OF PLASMAS
(2019)
Article
Astronomy & Astrophysics
M. Brodiano, N. Andres, P. Dmitruk
Summary: The study utilized DNS to investigate the interaction between linear waves and turbulence in the CMHD approach. Through parametric study and analysis of spatiotemporal spectra, linear waves such as Alfven waves were detected and their energy distribution quantified.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
R. Ferrand, F. Sahraoui, S. Galtier, N. Andres, P. Mininni, P. Dmitruk
Summary: Various exact laws governing compressible magnetohydrodynamic and compressible Hall-MHD turbulence have been derived in recent years. These laws not only have fundamental theoretical significance, but also can be used to estimate energy dissipation rate from spacecraft observations to address various problems related to solar wind and magnetospheric plasmas. In this study, numerical simulation data is used to analyze two of these laws, and the results show the equivalence of these laws in the inertial range, and reveal the relationship between the strength of the Hall effect and the amplitude of the cascade rate at sub-ion scales.
ASTROPHYSICAL JOURNAL
(2022)
Article
Computer Science, Interdisciplinary Applications
Mauro Fontana, Pablo D. Mininni, Oscar P. Bruno, Pablo Dmitruk
Summary: This method allows for the evolution of electromagnetic and velocity fields in conducting fluids with non-periodic boundaries. It has a small overhead compared to fast FFT-based pseudospectral methods and is applicable to various boundary conditions, including perfectly conducting walls or vacuum surroundings. By using a spectral Fourier continuation method, it accurately represents all fields and their spatial derivatives, allowing for efficient solution of Poisson equations with different boundaries.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Physics, Fluids & Plasmas
B. Balzarini, F. Pugliese, P. Dmitruk
Summary: In this study, direct numerical simulations of three-dimensional magnetohydrodynamics with a background magnetic field were performed, and test particles were introduced to explore their behavior in a turbulent electromagnetic environment. The focus was on the electric field terms, particularly the electronic pressure term, which was found to generate parallel acceleration of protons in contrast to the known perpendicular energization. By studying the electric field itself, the structures of the electronic pressure field that produce this parallel acceleration were identified.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
M. Brodiano, P. Dmitruk, N. Andres
Summary: We investigated the incompressible and compressible magnetohydrodynamic (MHD) energy cascade rates in the solar wind at various distances from the Sun using observations from the Parker Solar Probe mission and exact relations in fully developed turbulence. We found an increase in both the compressible and incompressible cascade rates as we approached the Sun, and the isothermal and polytropic cascade rates increased with increasing plasma compressibility. We also compared two exact relations for different levels of compressibility in the solar wind and observed similar cascade rates within the range of compressibility studied.
PHYSICS OF PLASMAS
(2023)
Article
Physics, Fluids & Plasmas
M. Fontana, P. D. Mininni, P. Dmitruk
Summary: In this study, a high-order numerical investigation is conducted on the dependence of dynamo onset on electromagnetic boundary conditions in convecting Boussinesq flows driven by temperature gradients. It is found that having one or two conducting boundaries greatly facilitates dynamo action. For the mixed boundary condition, the critical magnetic Reynolds number becomes independent of the Rayleigh number for sufficiently large Rayleigh numbers.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Computer Science, Interdisciplinary Applications
Mauro Fontana, Oscar P. Bruno, Pablo D. Mininni, Pablo Dmitruk
COMPUTER PHYSICS COMMUNICATIONS
(2020)
Article
Astronomy & Astrophysics
Laura F. Morales, Pablo Dmitruk, Daniel O. Gomez
ASTROPHYSICAL JOURNAL
(2020)
Article
Astronomy & Astrophysics
C. A. Gonzalez, P. Dmitruk, P. D. Mininni, W. H. Matthaeus
ASTROPHYSICAL JOURNAL
(2017)