A tunable excimer laser at 248 nm (KrF) and 193nm (ArF) has been used to monitor two-dimensional OH and NO distributions in the turbulent flame of a 100 kW natural gas burner. Spatially resolved fluorescence (spatial resolution better than 1.0 mm) from a 20 cm x 20 cm area is collected under single shot conditions. We describe the problems encountered when laser-induced fluorescence imaging tec...

A parallel adaptive mesh refinement (AMR) algorithm is proposed and applied to the predictions of both laminar and turbulent steady non-premixed compressible combusting flows. The parallel solution-adaptive algorithm solves the system of partial-differential equations governing two-dimensional axisymmetric laminar and turbulent compressible flows for reactive thermally perfect gaseous mixtures ...

The ability to model non-premixed combustion is very important; many practical combustion devices operate with non-premixed flames in the presence of turbulent flows (Vervisch & Poinsot, 1998). Non-premixed turbulent flames are characterized by a large spectrum of temporal and length scales. Additional complexity is added by the large number of unknowns and by the stiffness of highly nonlinear ...

The development of combustion systems to minimize the emission of pollutants and to increase the system’s efficiency involves modifications of the combustion process using premixed systems and highly turbulent swirl stabilized flames. However, these modifications of the combustion process usually lead to stability problems caused by the appearance of combustion-driven oscillations. Therefore, i...

A somewhat limited number of computationally tractable methods of simulating turbulent premixed combustion currently exist. Most of these methods either directly or indirectly require information about how fast flames propagate in turbulent flow fields. In this work a dynamic model for describing turbulent burning velocities in the context of large eddy simulation (LES) is presented. This model...

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 LES/FDF approach for turbulent combustion offers the benefits of both large eddy simulation (LES) to treat the turbulent flow, and the PDF approach to treat turbulence-chemistry interactions (in terms of the filtered density function, FDF). The approach is implemented as a particle mesh method and computationally the most expensive aspect is determining the change in particle composition ov...

This paper presents advanced image analysis methods for extracting information from high speed Planar Laser Induced Fluorescence (PLIF) data obtained from turbulent flames. The application of non-linear anisotropic diffusion filtering and of Active Contour Models (Snakes) is described to isolate flame boundaries. In a subsequent step, the detected flame boundaries are tracked in time using a fr...