Journal ArticleDOI
Progress-variable approach for large-eddy simulation of non-premixed turbulent combustion
Charles D. Pierce,Parviz Moin +1 more
TLDR
In this article, a new approach to chemistry modelling for large-eddy simulation of turbulent reacting flows is developed, whereby all of the detailed chemical processes are mapped to a reduced system of tracking scalars.Abstract:
A new approach to chemistry modelling for large-eddy simulation of turbulent reacting flows is developed. Instead of solving transport equations for all of the numerous species in a typical chemical mechanism and modelling the unclosed chemical source terms, the present study adopts an indirect mapping approach, whereby all of the detailed chemical processes are mapped to a reduced system of tracking scalars. Here, only two such scalars are considered: a mixture fraction variable, which tracks the mixing of fuel and oxidizer, and a progress variable, which tracks the global extent of reaction of the local mixture. The mapping functions, which describe all of the detailed chemical processes with respect to the tracking variables, are determined by solving quasi-steady diffusion-reaction equations with complex chemical kinetics and multicomponent mass diffusion. The performance of the new model is compared to fast-chemistry and steady-flamelet models for predicting velocity, species concentration, and temperature fields in a methane-fuelled coaxial jet combustor for which experimental data are available. The progress-variable approach is able to capture the unsteady, lifted flame dynamics observed in the experiment, and to obtain good agreement with the experimental data, while the fast-chemistry and steady-flamelet models both predict an attached flame.read more
Citations
More filters
Journal ArticleDOI
Dynamics and stability of lean-premixed swirl-stabilized combustion
Ying Huang,Vigor Yang +1 more
TL;DR: A comprehensive review of the advances made over the past two decades in this area is provided in this article, where various swirl injector configurations and related flow characteristics, including vortex breakdown, precessing vortex core, large-scale coherent structures, and liquid fuel atomization and spray formation are discussed.
Journal ArticleDOI
Large-eddy simulation of turbulent combustion
TL;DR: In this article, the authors highlight the fundamental differences between Reynolds-averaged Navier-Stokes (RANS) and LES combustion models for non-premixed and premixed turbulent combustion, identify some of the open questions and modeling issues for LES, and provide future perspectives.
Journal ArticleDOI
Progress in probability density function methods for turbulent reacting flows
TL;DR: Probability density function (PDF) methods have been widely used for modeling chemically reacting turbulent flows as discussed by the authors, where one models and solves an equation that governs the evolution of the one-point, one-time PDF for a set of variables that determines the local thermochemical and/or hydrodynamic state of a reacting system.
Journal ArticleDOI
Direct numerical simulation of turbulence in a nominally zero-pressure-gradient flat-plate boundary layer
Xiaohua Wu,Parviz Moin +1 more
TL;DR: In this article, a nominally zero-pressure-gradient incompressible boundary layer over a smooth flat plate was simulated for a continuous momentum thickness Reynolds number range of 80 ≤ Reθ ≤ 940.
Journal ArticleDOI
Large Eddy Simulations of gaseous flames in gas turbine combustion chambers
TL;DR: In this article, two types of LES in complex geometry combustors and of specific interest for aeronautical gas turbine burners are reviewed: (1) laboratory-scale combustors, without compressor or turbine, in which advanced measurements are possible and (2) combustion chambers of existing engines operated in realistic operating conditions.
References
More filters
Journal ArticleDOI
A dynamic subgrid‐scale eddy viscosity model
TL;DR: In this article, a new eddy viscosity model is presented which alleviates many of the drawbacks of the existing subgrid-scale stress models, such as the inability to represent correctly with a single universal constant different turbulent fields in rotating or sheared flows, near solid walls, or in transitional regimes.
Journal ArticleDOI
Laminar diffusion flamelet models in non-premixed turbulent combustion
TL;DR: In this paper, the steady laminar counterflow diffusion flame exhibits a very similar scalar structure as unsteady distorted mixing layers in a turbulent flow field, and the conserved scalar model is interpreted as the most basic flamelet structure.
Journal ArticleDOI
A dynamic subgrid‐scale model for compressible turbulence and scalar transport
TL;DR: Germano et al. as discussed by the authors generalized the dynamic subgrid-scale (SGS) model for the large eddy simulation (LES) of compressible flows and transport of a scalar.
Journal ArticleDOI
New Trends in Large-Eddy Simulations of Turbulence
Marcel Lesieur,Olivier Métais +1 more
TL;DR: In this article, a large-eddy simulation (LES) formalism, along with various subgrid-scale models developed since Smagorinsky's model, is presented, with an emphasis on the generation of coherent vortices.
Journal ArticleDOI
Conditional moment closure for turbulent combustion
TL;DR: Conditional moment closure (CMC) as mentioned in this paper is a well-known method for the prediction of turbulent reacting flows, with particular emphasis on combustion, and has been used extensively in the literature.