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Related papers: Thermal-Diffusional Instability in White Dwarf Fla…

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First results of simulations are presented which compute the dynamical evolution of a Chandrasekhar-mass white dwarf, consisting of equal amounts of carbon and oxygen, from the onset of violent thermonuclear burning, by means of a new…

Astrophysics · Physics 2009-09-25 M. Reinecke , W. Hillebrandt , J. C. Niemeyer

Diffusion flame streets, observed in non-premixed micro-combustion devices, align parallel to a shear flow. They are observed to occur in mixtures with high Lewis number ($Le$) fuels, provided that the flow Reynolds number, or the Peclet…

Fluid Dynamics · Physics 2024-07-03 Prabakaran Rajamanickam , Aiden Kelly , Joel Daou

Small-scale flickering buoyant diffusion flames in externally swirling flows were computationally investigated with a particular interest in identifying and characterizing various distinct dynamical behaviors of the flame oscillators under…

Fluid Dynamics · Physics 2023-03-29 Tao Yang , Yuan Ma , Peng Zhang

Steady propagation of premixed flames in straight channels is studied numerically using the on-shell approach. A first numerical algorithm for solving the system of nonlinear integro-differential on-shell equations is presented. It is based…

Fluid Dynamics · Physics 2018-09-26 Kirill A. Kazakov , Oleg G. Kharlanov

Models of diffusion in white dwarfs universally rely on the coefficients calculated by Paquette et al. (1986). We present new calculations of diffusion coefficients based on an advanced microscopic theory of dense plasmas and a numerical…

Solar and Stellar Astrophysics · Physics 2014-10-29 D. Saumon , C. E. Starrett , J. Daligault

We study a flame propagating in the gaseous combustible mixture with suspended inert particles. The gas is assumed to be transparent for the radiation emitted by the combustion products, while particles absorb and re-emit the radiation.…

Fluid Dynamics · Physics 2015-07-03 M. F. Ivanov , A. D. Kiverin , M. A. Liberman

The problem of flame propagation is studied as an example of unstable fronts that wrinkle on many scales is studied. The analytic tool of pole expansion in the complex plane is emloyed to address the interaction of the unstable growth…

adap-org · Physics 2011-08-19 Zeev Olami , Barak Galanti , Oleg Kupervasser , Itamar Procaccia

By introducing a simplified transport model of outer layers of white dwarfs we derive an analytical semi-empirical relation which constrains effective temperature-mass-radius for white dwarfs. This relation is used to classify recent data…

Solar and Stellar Astrophysics · Physics 2017-01-10 Elvis do A. Soares

We introduce a model of two coupled reaction-diffusion equations to describe the dynamics and propagation of flame fronts in random media. The model incorporates heat diffusion, its dissipation, and its production through coupling to the…

Condensed Matter · Physics 2016-08-15 N. Provatas , T. Ala-Nissila , M. Grant , K. R. Elder , L. Piché

The problem of flame propagation is studied as an example of unstable fronts that wrinkle on many scales. The analytic tool of pole expansion in the complex plane is employed to address the interaction of the unstable growth process with…

Pattern Formation and Solitons · Physics 2011-08-19 Oleg Kupervasser , Zeev Olami , Barak Galanti , Itamar Procaccia

We investigate effects of the magnetic field on the propagation of laminar flames of nuclear reactions taking place in white dwarfs (WDs) with the mass close to the Chandrasekhar limit. We calculate the velocities of laminar flames parallel…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Masamichi Kutsuna , Toshikazu Shigeyama

This study investigated the pulsating instability of burner-stabilized premixed CH4-O2 flames at various levels of CO2 dilution. Experiments were conducted using a water-cooled porous-plug burner of 18 mm diameter over a wide range of…

Fluid Dynamics · Physics 2026-01-23 Xiangyu Nie , Shuoxun Zhang , Shengkai Wang

Various flame tracking techniques are often used in hydrodynamic simulations. Their use is indispensable when resolving actual scale of the flame is impossible. We show that parameters defining "artificial flame" propagation found from…

Astrophysics · Physics 2007-05-23 Andrey V. Zhiglo

We present a dedicated search for new pulsating helium-atmosphere (DBV) white dwarfs from the Sloan Digital Sky Survey using the McDonald 2.1m Otto Struve Telescope. In total we observed 55 DB and DBA white dwarfs with spectroscopic…

Solar and Stellar Astrophysics · Physics 2022-03-30 Zachary P. Vanderbosch , J. J. Hermes , Don E. Winget , Michael H. Montgomery , Keaton J. Bell , Atsuko Nitta , S. O. Kepler

In this paper we investigate the acceleration of the expansion of premixed spherical flames and evolution of the cellular patterns on their surfaces. An asymptotic model is used for the simulations and a spectral numerical algorithm is…

Fluid Dynamics · Physics 2017-02-01 V. Karlin , G. Sivashinsky

Pulsating white dwarfs provide constraints to the evolution of progenitor stars. We revise He-burning stellar models, with particular attention to core convection and to its connection with the nuclear reactions powering energy generation…

Astrophysics · Physics 2009-11-07 Oscar Straniero , Inma Dominguez , Gianluca Imbriani , Luciano Piersanti

Wave dispersion in a pulsar plasma (a 1D, strongly magnetized, pair plasma streaming highly relativistically with a large spread in Lorentz factors in its rest frame) is discussed, motivated by interest in beam-driven wave turbulence and…

Plasma Physics · Physics 2019-07-31 M. Z. Rafat , D. B. Melrose , A. Mastrano

The propagation of unstable interfaces is at the origin of remarkable patterns that are observed in various areas of science as chemical reactions, phase transitions, growth of bacterial colonies. Since a scalar equation generates usually…

Analysis of PDEs · Mathematics 2014-01-31 Michal Kolwalczyk , Benoit Perthame , Nicolas Vauchelet

We present a numerical model to study the behavior of thermonuclear flames in the discontinuity approximation. This model is applied to investigate the Landau-Darrieus instability under conditions found in Type Ia supernova explosions of…

Astrophysics · Physics 2007-05-23 F. K. Roepke , W. Hillebrandt , J. C. Niemeyer

The morphology of flame fronts propagating in reactive systems comprised of randomly positioned, point-like sources is studied. The solution of the temperature field and the initiation of new sources is implemented using the superposition…

Fluid Dynamics · Physics 2017-07-19 Fredric Lam , XiaoCheng Mi , Andrew J. Higgins