A new modeling strategy is developed to introduce tabulated chemistry methods in LES of turbulent premixed combustion. The objective is to recover the correct laminar flame propagation speed of the filtered flame front when subgrid scale turbulence vanishes. The filtered flame structure is mapped by 1-D filtered laminar premixed flames. Closure of the filtered progress variable and the energy b...

A deflagration-to-detonation transition (DDT) can occur in environments ranging from experimental and industrial systems to astrophysical thermonuclear (type Ia) supernovae explosions. Substantial progress has been made in explaining the nature of DDT in confined systems with walls, internal obstacles, or preexisting shocks. It remains unclear, however, whether DDT can occur in unconfined media...

In this paper, we present a knowledge-assisted approach for studying turbulent combustion simulation data. To understand the dynamic mechanisms of extinction and reignition in turbulent flames, scientists need to validate known relationships and reveal hidden ones among multiple variables. Based on the domain knowledge and questions posted by the scientists, we have designed an algorithm that h...

Simultaneous planar measurements of laser-induced incandescence (LII) and Laser-Induced Fluorescence of OH radical were carried out in turbulent jet flames from a simple jet, precessing jet and bluff body burner firing natural gas. These flames span a wide range of global mixing rates and sooting characteristics, and are selected because measurements of total NOx emissions, radiant fraction and...

We describe a simple experimental arrangement for emission tomographic measurements of radicals in flames. Experimental determinations of two-dimensional spatially resolved distributions of excited-state CH in atmospheric-pressure flames are presented. Calibration of the distributions to absolute number densities is performed with a Rayleigh scattering technique. Methods for simultaneous record...

This study discusses the design of a new experimental platform, the Hybrid Flame Analyzer (HFA) to measure burning velocity of gas, dust, and hybrid (gas and dust) premixed flames. The HFA is used to analyze a particle–gas–air system of coal dust particles (75–90 lm and 106–120 lm) in a premixed CH4–air (/g = 0.8, 1.0 and 1.2) flame. Experimental results show that particles usually increase the...

0010-2180/$ see front matter 2009 The Combust doi:10.1016/j.combustflame.2009.03.017 * Corresponding author. Fax: +1 203 432 7654. E-mail address: [email protected] (A. Go 1 Present address: Department of Bioengineering, Im We propose a highly turbulent counterflow flame as a very useful benchmark of complexity intermediate between laminar flames and practical systems. By operating in a...

Video data from experiments on the dynamics of two-dimensional flames are analyzed. The Karhunen-Lo6ve (KL) analysis is used to identify the dominant spatial structures and their temporal evolution for several dynamical regimes of the flames. A data analysis procedure to extract and process the boundaries of flame cells is described. It is shown how certain spatial structures are associated wit...