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Related papers: Small-scale intermittency of premixed turbulent fl…

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Given the need to develop zero-carbon combustors for power and aircraft engine applications, $S_d$ of a turbulent premixed flame, especially for H$_2$-air, is of immediate interest. The present study investigates 3D DNS cases of premixed…

We report analytical and numerical investigations of sub-ion-scale turbulence in low-beta plasmas, focusing on the spectral properties of the fluctuations and electron heating. In the isothermal limit, the numerical results strongly support…

High Energy Astrophysical Phenomena · Physics 2022-08-05 Muni Zhou , Zhuo Liu , Nuno F. Loureiro

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…

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

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

Computed flame motion through and between swirling eddys exhibits a maximum advancement rate which is related to the time duration of flame motion between eddys. This eddy spatial structure effect upon the apparent turbulent flame speed…

chao-dyn · Physics 2008-02-03 Wm. T. Ashurst

Magnetic fluctuations in the solar wind are distributed according to Kolmogorov's power law $f^{-5/3}$ below the ion cyclotron frequency $f_{ci}$. Above this frequency, the observed steeper power law is usually interpreted in two different…

Astrophysics · Physics 2009-11-13 O. Alexandrova , V. Carbone , P. Veltri , L. Sorriso-Valvo

A new unsteady flamelet model is developed to be used for sub-grid modeling and coupling with the resolved flow description for turbulent combustion. Difficulties with prior unsteady flamelet models are identified. The model extends the…

Fluid Dynamics · Physics 2024-02-02 William A. Sirignano

The work investigates the response dynamics of non-premixed jet flame to blast waves that are incident along the jet axis. In the present study, blast waves, generated using the wire-explosion technique, are forced to sweep across a…

Fluid Dynamics · Physics 2026-01-14 Akhil Aravind , Gautham Vadlamudi , Saptarshi Basu

A Rayleigh-Taylor (RT) unstable flame is a thin burning interface sandwiched between heavy fuel and light ash layers. RT unstable flames play an important role in complex systems like novel aviation turbine engines, storage facilities for…

Fluid Dynamics · Physics 2026-03-13 Elizabeth P. Hicks

Fluctuations due to a super-position of uncorrelated Lorentzian pulses with a random distribution of amplitudes and duration times are considered. These are demonstrated to be strongly intermittent in the limit of weak pulse overlap,…

Plasma Physics · Physics 2018-03-14 O. E. Garcia , A. Theodorsen

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…

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-scale intermittency is a widely observed phenomenon in convective surface layer turbulence that induces non-Gaussian temperature statistics, while such signature is not observed for velocity signals. Although approaches based on…

Fluid Dynamics · Physics 2021-09-15 Subharthi Chowdhuri , Giovanni Iacobello , Tirtha Banerjee

We study the growth of small-scale inhomogeneities of the density of particles floating in weakly nonlinear, small-amplitude, surface waves. Despite the amplitude smallness, the accumulated effect of the long-time evolution may produce…

Chaotic Dynamics · Physics 2012-10-23 M. Vucelja , I. Fouxon

Numerical simulations are used to determine the influence of the non-local and local interactions on the intermittency corrections in the scaling properties of 3D turbulence. We show that neglect of local interactions leads to an enhanced…

Fluid Dynamics · Physics 2016-09-08 J. -P. Laval , B. Dubrulle , S. Nazarenko

Features of the turbulent cascade are investigated for various datasets from three different turbulent flows. The analysis is focused on the question as to whether developed turbulent flows show universal small scale features. To answer…

Fluid Dynamics · Physics 2018-06-19 Nico Reinke , Andre Fuchs , Daniel Nickelsen , Joachim Peinke

Turbulent motions due to flux-driven thermal convection is investigated by numerical simulations and stochastic modelling. Tilting of convection cells leads to the formation of sheared flows and quasi-periodic relaxation oscillations for…

Fluid Dynamics · Physics 2020-08-26 G. Decristoforo , A. Theodorsen , O. E. Garcia

We extend a model for turbulence-flame interactions (TFI) to consider astrophysical flames with a particular focus on combustion in type Ia supernovae. The inertial range of the turbulent cascade is nearly always under-resolved in…

Solar and Stellar Astrophysics · Physics 2015-06-18 Aaron P. Jackson , Dean M. Townsley , Alan C. Calder

In this paper we discuss the dynamical features of intermittent fluctuations in homogeneous shear flow turbulence. In this flow the energy cascade is strongly modified by the production of turbulent kinetic energy related to the presence of…

Chaotic Dynamics · Physics 2007-05-23 P. Gualtieri , C. M Casciola , R. Benzi , G. Amati , R. Piva