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Although experimental evidence for the correlation between early flame kernel development and cycle-to-cycle variations (CCV) in spark ignition (SI) engines was provided long ago, there is still a lack of fundamental understanding of early…

Although the evolution of premixed flames in turbulence has been frequently studied, it is not well understood how small flames interact with large-scale turbulent flow motion. Since this question is of practical importance for the…

Fluid Dynamics · Physics 2020-02-04 Tobias Falkenstein , Seongwon Kang , Heinz Pitsch

From experimental spark ignition (SI) engine studies, it is known that the slow-down of early flame kernel development caused by the ($\mathrm{Le}>1$)-property of common transportation-fuel/air mixtures tends to increase cycle-to-cycle…

Fluid Dynamics · Physics 2020-10-08 Tobias Falkenstein , Hongchao Chu , Mathis Bode , Seongwon Kang , Heinz Pitsch

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

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…

This paper analyzes turbulence-chemistry interactions for an n-dodecane-air flame, focusing on the degree to which fuel oxidation pathways change in turbulent flames relative to their corresponding laminar flames. This work is based on a…

Computational Physics · Physics 2018-10-04 D. Dasgupta , W. Sun , M. Day , A. J. Aspden , nd T. Lieuwen

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

Premixed flames exhibit different asymptotic regimes of interaction between heat release and turbulence depending on their respective length scales. At high Karlovitz number, the dilatation caused by heat release does not have any relevant…

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

Influences of reaction zone thickening and local extinctions on the burning rate of extremely turbulent hydrogen-enriched methane-air flames are investigated using simultaneous planar laser-induced fluorescence of formaldehyde molecule and…

Fluid Dynamics · Physics 2020-12-01 Sajjad Mohammadnejad , Qiang An , Patrizio Vena , Sean Yun , Sina Kheirkhah

(Abridged) Direct numerical simulations of the interaction of a premixed flame with driven, subsonic, homogeneous, isotropic, Kolmogorov-type turbulence in an unconfined system are used to study the mechanisms determining the turbulent…

High Energy Astrophysical Phenomena · Physics 2011-06-21 Alexei Y. Poludnenko , Elaine S. Oran

Lean turbulent premixed hydrogen/air flames have substantially increased flame speeds, commonly attributed to differential diffusion effects. In this work, the effect of turbulence on lean hydrogen combustion is studied through Direct…

Fluid Dynamics · Physics 2024-08-20 Matthew X. Yao , Guillaume Blanquart

An a priori analysis of a DNS database of turbulent lean premixed methane flames is presented considering the relative effects of turbulence and LES filtering, along with a potential modelling approach for LES with finite-rate chemistry.…

Fluid Dynamics · Physics 2018-06-27 A J Aspden , N Zettervall , C Fureby

In this contribution, velocity and its dissipation spectra in turbulent non-premixed jet flames are investigated by using two Direct Numerical Simulation (DNS) databases of temporally evolving jets with different bulk jet Reynolds numbers.…

Fluid Dynamics · Physics 2019-10-04 Ali Shamooni , Alberto Cuoci , Tiziano Faravelli , Amsini Sadiki

Reactive flows in confined spaces involve complex flame-wall interaction (FWI). This work aims to gain more insights into the physics of the premixed near-wall flame and the wall heat flux as an important engineering relevant quantity. Two…

Fluid Dynamics · Physics 2025-10-31 Kunlin Li , Chenlin Guo , Zhaofan Zhu , Haiou Wang , Lipo Wang

Evolution of fuel droplet evaporation zone and its interaction with the propagating flame front are studied in this work. A general theory is developed to describe the evolutions of flame propagation speed, flame temperature, droplet…

Fluid Dynamics · Physics 2022-12-14 Qiang Li , Chang Shu , Huangwei Zhang

Diffusive transport of mass occurs at small scales in turbulent premixed flames. As a result, multicomponent mass diffusion, which is often neglected in direct numerical simulations (DNS) of premixed combustion, has the potential to impact…

Fluid Dynamics · Physics 2022-07-20 Aaron J. Fillo , Peter E. Hamlington , Kyle E. Niemeyer

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

We investigate and model pressure effects on the turbulent burning velocity over a wide range of pressures and turbulence intensities with the direct numerical simulation (DNS) of statistically planar turbulent premixed flames for lean…

Fluid Dynamics · Physics 2019-11-26 Zhen Lu , Yue Yang

A series of Direct Numerical Simulations (DNS) of lean methane/air flames was conducted in order to investigate the enhancement of the turbulent flame speed and modifications to the reaction layer structure associated with the systematic…

Fluid Dynamics · Physics 2020-08-18 Antonio Attili , Stefano Luca , Dominik Denker , Fabrizio Bisetti , Heinz Pitsch
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