A large eddy simulation (LES) model was developed to simulate the combustion process in a spark-assisted homogeneous charge compression ignition (SACI) engine. First, an ignition and flame propagation model based on a reaction progress variable is presented. The reaction progress variable is defined based on the normalized cumulative heat release. Transport equation for the progress variable is...

Multiple flame-flame interactions in premixed combustion are investigated using Direct Numerical Simulations of twin turbulent V-flames for a range of turbulence intensities and length scales. Interactions are identified using a novel Automatic Feature Extraction (AFE) technique, based on data registration using the Dual-Tree Complex Wavelet Transform. Information on the time, position and type...

The usage of direct numerical simulations for research turbulent combustion space propulsion applications is explored. With this goal in mind, the near injection a fuel-rich methane–oxygen flame at 20 bar simulated using massively parallelized solver. statistical properties relevant physical fields are examined to study interactions between turbulence and combustion. This analysis complemented ...

In an opposed-jet diffusion flame experiment, under certain conditions, after the extinction of the diffusion flame, an edge flame can be obtained. This ring-shaped edge flame was first reported in 1959 by Potter and Butler but received little attention. It was reported again recently in a numerical and an experimental work and is responsible for an interesting transition between two distinct b...

The objective of this work is to provide physical insight into the mechanisms governing flame–turbulence interactions and explore impact ubiquitous Darrieus–Landau instability on propagation. It based hydrodynamic theory premixed flames that considers flame thickness much smaller than all other fluidynamical length scales. In asymptotic limit, thus confined a surface whilst diffusion reaction p...

Mesoscale internal combustion engines for a variety of new combustion system applications have dimensions that are far smaller than conventional macroscale engines, yet unlike true microscale engines allow significant mean flow and turbulence to be created in the combustion chamber by the injection process. The resulting flow allows minimization of the combustion time by augmenting flame propag...

Dynamic models for large eddy simulation of the G-equation of turbulent premixed combustion are proposed and tested in forced homogeneous isotropic turbulence. The basic idea is to represent the ‘‘filtered propagation term’’ as ‘‘propagation of the filtered front at higher speed,’’ where the enhanced filtered-front speed is modeled. The validity of the linear relation between the turbulent flam...

Large eddy simulations in a wall bounded domain are conducted in order to study the kinematic structure of premixed turbulent flame. The linear model presents a prospect of isolating the effects of each of the physical mechanisms that underly turbulent combustion. In the present study, we investigate the flame structure in the absence of thermodyamic effects such as heat release using this mode...

Direct Numerical Simulations (DNS) have been conducted to study the response of initially laminar spherical premixed methane–air flame kernels to successively higher turbulence intensities at five different equivalence ratios. The numerical experiments include a 16-species/25-step skeletal mechanism for methane oxidation and a multicomponent molecular transport model. Highly turbulent condition...