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Related papers: Thin Reaction Zones in Highly Turbulent Medium

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We investigate diffusion in supersonic, turbulent, compressible flows. Supersonic turbulence can be characterized as network of interacting shocks. We consider flows with different rms Mach numbers and where energy necessary to maintain…

Astrophysics · Physics 2009-11-07 Ralf S. Klessen , Doug N. C. Lin

We present the results of a Direct Numerical Simulation of a particle-laden spatially developing turbulent boundary layer up to Re{\theta} = 2500. Two main features differentiate the behavior of inertial particles in a zero-…

Context. In stellar interiors, rotation is able to drive turbulent motions, and the related transport processes have a significant influence on the evolution of stars. Turbulent mixing in the radiative zones is currently taken into account…

Solar and Stellar Astrophysics · Physics 2013-01-25 Vincent Prat , François Lignières

Direct numerical simulations of free round jets at a Reynolds number ($Re_{D}$) of $5000$, based on jet diameter ($D$) and jet-exit bulk velocity ($U_{e}$), are performed to study jet turbulence characteristics at supercritical pressures.…

Fluid Dynamics · Physics 2021-08-04 Nek Sharan , Josette Bellan

In this paper the propagation of acoustic plane waves in turbulent, fully developed flow is studied by means of an experimental investigation carried out in a straight, smooth-walled duct.The presence of a coherent perturbation, such as an…

Fluid Dynamics · Physics 2018-12-31 H. Tiikoja , F. Auriemma , J. Lavrentjev

Using direct numerical simulations of turbulent thermal convection for Rayleigh number ($\mathrm{Ra}$) between $10^6$ and $10^8$ and unit Prandtl number, we derive scaling relations for viscous dissipation in the bulk and in the boundary…

Fluid Dynamics · Physics 2018-04-09 Shashwat Bhattacharya , Ambrish Pandey , Abhishek Kumar , Mahendra K. Verma

We consider a special type of fast reaction-diffusion systems in which the coefficients of the reaction terms of the two substances are much larger than those of the diffusion terms while the diffusive motion to the substrate is negligible.…

Numerical Analysis · Mathematics 2024-04-30 Yu Zhao , Zhennan Zhou

A scaling relation for the high frequency regime of streamwise energy spectra (in frequency domain) in the near-wall region is proposed. This is based on the dimensional analysis approach of \cite{perry1977} and \cite{Zamalloa2014} together…

Fluid Dynamics · Physics 2018-11-07 B. Ganapathisubramani

We examine the applicability of the weak wave turbulence theory in explaining experimental scaling results obtained for the diffusion and relative diffusion of particles moving on turbulent surface waves. For capillary waves our theoretical…

Chaotic Dynamics · Physics 2007-09-23 Victor M. Eguiluz , Mogens T. Levinsen , Preben Alstrom

Experiments have shown that micron-sized distributed surface roughness can significantly promote transition in a three-dimensional boundary layer dominated by crossflow insta- bility. This sensitive effect has not yet been fully explained…

Fluid Dynamics · Physics 2018-12-05 Jiyang He , Adam Butler , Xuesong Wu

We study a reaction-diffusion system of partial differential equations, which can be taken to be a basic model for criminal activity. We show that the assumption of a populations natural tendency towards crime significantly changes the…

Analysis of PDEs · Mathematics 2013-07-12 Henri Berestycki , Nancy Rodriguez , Lenya Ryzhik

The mechanisms governing the transition to turbulence in natural convection boundary layers along strongly heated vertical walls remain neither very clear nor well understood, because of the lack of experiments and the difficulties of…

Fluid Dynamics · Physics 2008-12-23 Thierry De Larochelambert

We examine the effects of turbulent intermittency on the deflagration to detonation transition (DDT) in Type Ia supernovae. The Zel'dovich mechanism for DDT requires the formation of a nearly isothermal region of mixed ash and fuel that is…

Astrophysics · Physics 2009-11-13 Liubin Pan , J. Craig Wheeler , John Scalo

We discuss a new phenomenon of turbulent thermal diffusion associated with turbulent transport of aerosols in the atmosphere and in laboratory experiments. The essence of this phenomenon is the appearance of a nondiffusive mean flux of…

Astrophysics · Physics 2020-01-29 A. Eidelman , T. Elperin , N. Kleeorin , A. Krein , I. Rogachevskii , J. Buchholz , G. Gruenefeld

Turbulent radiative mixing layers (TRMLs), where shear-driven turbulence between dense and diffuse gas produces rapidly cooling intermediate-temperature gas, are ubiquitous in the interstellar and circumgalactic media. Using a quasi-steady…

Astrophysics of Galaxies · Physics 2025-11-18 Prateek Sharma , Arnav Kumar , Dipayan Datta , Arif Babul , Rishita Das , Konduri Aditya

In this work we study the spreading dynamics of tiny liquid droplets on solid surfaces in the case where the ends of the molecules feel different interactions with respect to the surface. We consider a simple model of dimers and short…

Condensed Matter · Physics 2009-10-28 M. Haataja , J. A. Nieminen , T. Ala-Nissila

Context. Tens of light hydrides and small molecules have now been detected over several hundreds sight lines sampling the diffuse interstellar medium (ISM) in both the Solar neighbourhood and the inner Galactic disk. They provide…

Astrophysics of Galaxies · Physics 2015-06-22 Benjamin Godard , Edith Falgarone , Guillaume Pineau Des Forêts

Theory of diffusion-mediated reactions is already established for the target problem in the dilute limit, where the immobile target is surrounded by many quenchers. For lattice random walks in the crowded situation, each quencher is…

Statistical Mechanics · Physics 2015-05-13 Kazuhiko Seki , M. Tachiya

Dynamics of spreading of small droplets on surfaces has been studied by the molecular dynamics method. Simulations have been performed for mixtures of solvent and dimer, and solvent and tetramer droplets. For solvent particles and dimers,…

Condensed Matter · Physics 2009-10-22 J. A. Nieminen , T. Ala- Nissila

We consider transition to strong turbulence in an infinite fluid stirred by a gaussian random force. The transition is {\bf defined} as a first appearance of anomalous scaling of normalized moments of velocity derivatives (dissipation…

Fluid Dynamics · Physics 2017-08-02 Victor Yakhot , Diego Donzis