English
Related papers

Related papers: Distributed Flames in Type Ia Supernovae

200 papers

Direct Numerical Simulation data obtained earlier from two statistically 1D, planar, fully-developed, weakly turbulent, single-step-chemistry, premixed flames characterized by two significantly different (7.53 and 2.50) density ratios…

We perform 2D and 3D kinetic simulations of reconnection-mediated turbulent flares in a magnetized electron-positron plasma, with weak and strong radiative cooling. Such flares can be generated around neutron stars and accreting black…

High Energy Astrophysical Phenomena · Physics 2021-11-17 J. Nättilä , A. M. Beloborodov

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

Lean premixed hydrogen-air flames are strongly affected by thermodiffusive (TD) instabilities, which can alter the flame structure and enhance the local reactivity many-fold. Two recent models (Howarth et al. (Combust.~Flame 253, 2023) and…

Annular chambers, consisting of multiple flame nozzles, are frequently used in many industrial processes, for example, rocket engines and gas turbines. In the study, we proposed a novel approach to the problem of annular combustion with…

Fluid Dynamics · Physics 2025-03-04 Tao Yang , Yuan Ma , Peng Zhang

We present the first vertically resolved hydrodynamic simulations of a laterally propagating, deflagrating flame in the thin helium ocean of a rotating accreting neutron star. We use a new hydrodynamics solver tailored to deal with the…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Yuri Cavecchi , Anna L. Watts , Jonathan Braithwaite , Yuri Levin

Following up on earlier work on this topic (Reinecke et al. 1999, A&A 347, pp. 724 and 739), we present an improved set of numerical models for simulations of white dwarfs exploding as Type Ia supernovae (SNe Ia). Two-dimensional…

Astrophysics · Physics 2009-11-07 M. Reinecke , W. Hillebrandt , J. C. Niemeyer

Large hydrocarbon fuels are used for ground and air transportation and will be for the foreseeable future. Despite their extensive use, turbulent combustion of large hydrocarbon fuels, remains relatively poorly understood and difficult to…

Fluid Dynamics · Physics 2022-01-04 Aaron J. Fillo , Jonathan Bonebrake , David L. Blunck

In this paper, neural network (NN)-based models are generated to replace flamelet tables for sub-grid modeling in large-eddy simulations of a single-injector liquid-propellant rocket engine. In the most accurate case, separate NNs for each…

Fluid Dynamics · Physics 2020-12-03 Zeinab Shadram , Tuan M. Nguyen , Athanasios Sideris , William A. Sirignano

In this paper we consider ignition-temperature, first-order reaction model of thermo-diffusive combustion that describes dynamics of thick flames arising in a theory of combustion of hydrogen-oxygen and ethylene-oxygen mixtures. These…

Chaotic Dynamics · Physics 2017-04-03 Nathan Kilker , Dmitry Golovaty , Peter V. Gordon , Leonid Kagan , Gregory I. Sivashinsky

Inter-scale kinetic energy transfer in turbulent flows is accompanied by very intense and intermittent spatial-temporal fluctuations. Such intermittency is expected to be particularly prominent in premixed flames, where heat release,…

Fluid Dynamics · Physics 2024-05-20 Vladimir A. Sabelnikov , Andrei N. Lipatnikov

We have developed a phenomenological turbulent model with one-dimensional (1D) simulation based on Reynolds decomposition. Using this method, we have systematically studied models with different effects of compression, mixing length…

High Energy Astrophysical Phenomena · Physics 2024-01-24 Shunsuke Sasaki , Tomoya Takiwaki

This study explores heat and turbulent modulation in three-dimensional multiphase Rayleigh-B\'enard convection using direct numerical simulations. Two immiscible fluids with identical reference density undergo systematic variations in…

Fluid Dynamics · Physics 2024-08-26 Abbas Moradi Bilondi , Nicolò Scapin , Luca Brandt , Parisa Mirbod

The present paper seeks to determine the mechanism of flame acceleration and transition to detonation when a turbulent flame preceded by a shock interacts with a single obstruction in its path, taken as a cylindrical obstacle or a wall in…

Fluid Dynamics · Physics 2018-06-12 Willstrong Rakotoarison , Brian Maxwell , Andrzej Pekalski , Matei I. Radulescu

This work presents a new approach for premixed turbulent combustion modeling based on convolutional neural networks (CNN). We first propose a framework to reformulate the problem of subgrid flame surface density estimation as a machine…

Fluid Dynamics · Physics 2019-08-02 C. J. Lapeyre , A. Misdariis , N. Cazard , D. Veynante , T. Poinsot

Significant progress has been made on the model development for simulating turbulent reacting flows. As a consequence, we are currently in a position where key-physical aspects of fairly complex combustion processes are well understood at a…

Fluid Dynamics · Physics 2020-12-17 Matthias Ihme

This paper presents a flame-height correlation for laminar to transition-to-turbulent regime diffusion flames. Flame-height measurements are obtained by means of numerical and experimental studies in which three high definition cameras were…

Data from a three-dimensional Direct Numerical Simulation of a turbulent premixed Bunsen flame at a low global Lewis number are analyzed to address the effects of the curvature on the local flame front. For this purpose, the chemical…

Theoretical and observational studies on the turbulence of the interstellar medium developed fast in the past decades. The theory of supersonic magnetized turbulence, as well as the understanding of projection effects of observed…

Astrophysics of Galaxies · Physics 2015-05-18 D. Falceta-Goncalves , A. Lazarian , M. Houde

Surface roughness significantly impacts transition to turbulence, especially over high-speed, blunt geometries where surface ablation is necessary to mitigate heat loads during atmospheric entry. Inspired by sand-grain roughness experiments…

Fluid Dynamics · Physics 2026-02-04 Sean Dungan , Mateus Braga , Robyn Macdonald , Christoph Brehm
‹ Prev 1 8 9 10 Next ›