The Conditional Moment Closure (CMC) model provides a means of closing the subgrid terms for the reaction rates through the assumption that departures of the mean filtered reaction rate (conditional on a mixture fraction or progress variable) are small. Turbulentchemistry interaction is incorporated through a conditional scalar dissipation. To date, all Large Eddy Simulation implementations of ...

The lagrangian point of view is adopted to study turbulent premixed combustion. The evolution of the volume fraction of combustion products is established by the Reynolds transport theorem. It emerges that the burned-mass fraction is led by the turbulent particle motion, by the flame front velocity, and by the mean curvature of the flame front. A physical requirement connecting particle turbule...

Contour Advection with Surgery (CAS) is used to simulate turbulent premixed combustion. This paper presents results from calculations of methane/air mixtures and ethylene/air mixtures with equivalence ratios ranging from 0.8 to 1.6 with different turbulence intensities. The positions, thicknesses and half-angles of the turbulent flame zones are compared for each case by plotting contour maps of...

In this study a multi-objective genetic algorithm approach is developed for determining new reaction rate parameters for the combustion of kerosene/air mixtures. The multi-objective structure of the genetic algorithm employed allows for the incorporation of both perfectly stirred reactor and laminar premixed flame data into the inversion process, thus producing more efficient reaction mechanisms.

Introduction In order to overcome the pollutant emission limitations the use of homogeneous charge compression ignition (HCCI) mode must be considered in direct injection diesel engine using biodiesel fuel. HCCI mode reduces PM and NOx emissions without penalize the performances [1]. This occurs because the combustion develops with low temperature and burns a premixed air/fuel mixture. Biodiese...

This paper deals with the analysis of a set of measurements collected on a lean premixed combustion process operating in a limit cycle. Due to the fact that the data are collected in closed-loop and the system has no external excitation, the identi®cation task is particularly challenging. This work mainly focuses on the issue of the feasibility of the identi®cation task. It will be shown that, ...

The dynamics of major flow structures were studied in a gas turbine model combustor for perfectly premixed swirlstabilized flames under a variety of reacting and non-reacting conditions using high-repetition-rate laser diagnostics. The studied combustor is a target case for the International Workshop on Advanced Measurement Techniques and Computational Methods for Premixed and Partially Premixe...

Abstract A flamelet-based approach that accounts for turbulence-chemistry interaction has been formulated to simulate NOx formation in turbulent lean premixed combustion. In the simulations, the species NO is transported and solved with the chemical source term being modelled through its formation in flame fronts and its formation rate in post-flame regions. The flame-front NO and post-flame NO...

Fuel droplets in combustors interact strongly with flames and turbulence in practical liquid-fueled combustors of terrestrial and aerial propulsion systems (Williams 1965; Sirignano 1999). Although a great deal of physical understanding has been achieved in purely gaseous combustion over the last century, not much is currently known about spray combustion at the fundamental level. In this short...