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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

Premixed flames are susceptible to hydrodynamic and thermodiffusive instabilities that wrinkle the flame front and lead to complex multiscale patterns. They strongly impact the flame propagation and dynamics, increasing the speed of a…

Numerical modeling of the edge and scrape-off layer (SOL) must account for atomic processes such as hydrogenic ionization and recombination, charge-exchange, and line radiation. Their reaction rates depend non-linearly on density and…

Plasma Physics · Physics 2026-04-01 Konrad Eder , Wladimir Zholobenko , Andreas Stegmeir , Kaiyu Zhang , Frank Jenko

This study investigates the effect of increasing strain rate on thermodiffusively unstable, lean premixed hydrogen flames in a 2D counterflow configuration through detailed-chemistry numerical simulations for the first time. The analysis of…

Thermodiffusive instabilities can have a leading order effect on flame propagation for lean premixed hydrogen flames. Many simulation studies have been performed to study this effect, but almost exclusively in two-dimensional (2D) or domain…

Fluid Dynamics · Physics 2023-12-20 Wen Xu , Berger Lukas , Cai Liming , Parente Alessandro , Pitsch Heinz

The scaling of turbulent premixed flames is typically described by correlations derived for unity-Lewis-number fuels. However, their validity for hydrogen (H$_{2}$) remains uncertain due to the thermodiffusive effects associated with its…

A high-pressure hydrogen micromix combustor has been investigated using direct numerical simulation with detailed chemistry to examine the flame structure and stabilisation mechanism. The configuration of the combustor was based on the…

Different approaches to the nonlinear dynamics of premixed flames exist in the literature: equations based on developments in a gas ex- pansion parameter, weak nonlinearity approximation, potential model equation in a coordinate-free form.…

Classical Physics · Physics 2007-05-23 Bruno Denet , Vitaly Bychkov

We propose a predictive model of the turbulent burning velocity over a wide range of conditions. The model consists of sub models of the stretch factor and the turbulent flame area. The stretch factor characterizes the flame response of…

Fluid Dynamics · Physics 2024-07-25 Zhen Lu , Yue Yang

This study presents methane-air counterflow simulations, in computationally efficient similar form, allowing combustible mixtures to flow from one or both directions in order to learn more about multi-branched propagating flame structures…

Fluid Dynamics · Physics 2020-07-22 Claudia-F. López-Cámara , Albert Jordà Juanós , William A. Sirignano

Large-eddy simulations (LES) of a planar turbulent lean hydrogen-air jet flame at Re = 11000 are performed using a tabulated flamelet model based on mixture-averaged diffusion that incorporates detailed transport, including differential and…

In the present study, we conduct direct numerical simulations to investigate the near-wall dynamics of compressible turbulent boundary layers at the free-stream Mach number of 6 laden with heavy particles. By inspecting the instantaneous…

Fluid Dynamics · Physics 2025-05-14 Ming Yu , Lihao Zhao , Yibin Du , Xianxu Yuan , Chunxiao Xu

The problem of premixed flame propagation in wide horizontal tubes is revisited. Employing the on-shell description of flames with arbitrary gas expansion, a nonlinear second-order differential equation for the front position of steady…

Fluid Dynamics · Physics 2015-05-30 Kirill A. Kazakov

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

The fractal scaling properties of turbulent premixed flame fronts have been investigated and considered for modelling sub-grid scales in the Large-Eddy-Simulation framework. Since the width of such thin reaction fronts cannot be resolved…

Fluid Dynamics · Physics 2017-02-17 Francesco Battista , Guido Troiani , Francesco Picano

Understanding how intrinsically fast hydrogen-air premixed flames can be rendered much faster in turbulence is crucial for systematically developing hydrogen-based gas turbines and spark ignition engines. Here, we present fundamental…

Fluid Dynamics · Physics 2025-01-30 Yuvraj , Hong G. Im , Swetaprovo Chaudhuri

The study investigates the response dynamics of premixed jet flames when incident with blast waves along the jet axis. In the present work, blast waves are generated using the wire-explosion technique. The generated blast wave interacts…

Fluid Dynamics · Physics 2024-04-22 Akhil Aravind , Gautham Vadlamudi , Saptarshi Basu

Premixed flames propagating in horizontal tubes are observed to take on shape convex towards the fresh mixture, which is commonly explained as a buoyancy effect. A recent rigorous analysis has shown, on the contrary, that this process is…

Fluid Dynamics · Physics 2015-12-16 Hazem El-Rabii , Kirill A. Kazakov

Analyzed in this paper are three-dimensional Direct Numerical Simulation (DNS) data obtained from seven statistically planar and one-dimensional, lean complex-chemistry hydrogen-air flames propagating in a box with forced turbulence. The…

Fluid Dynamics · Physics 2025-04-09 H. C. Lee , P. Dai , M. Wan , Andrei N. Lipatnikov

Three-dimensional numerical simulations of canonical statistically-steady statistically-planar turbulent flames have been used in an attempt to produce distributed burning in lean methane and hydrogen flames. Dilatation across the flame…

Fluid Dynamics · Physics 2019-05-22 A. J. Aspden , M. S. Day , J. B. Bell