Scalar dissipation rate transport conditional on flow topologies in different regimes of premixed turbulent combustion
نویسندگان
چکیده
منابع مشابه
Investigation of scalar dissipation rate fluctuations in non-premixed turbulent combustion using a stochastic approach
Turbulent fluctuations of the scalar dissipation rate are well known to have a strong impact on ignition and extinction in non-premixed combustion. In the present study the influence of stochastic fluctuations of the scalar dissipation rate on the solution of the flamelet equations is investigated. A one-step irreversible reaction is assumed. The system can thereby be described by the solution ...
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where DZ is the diffusion coefficient of the mixture fraction. The scalar dissipation rate appears in many models for turbulent non-premixed combustion as, for instance, the flamelet model (Peters (1984), Peters (1987)), the Conditional Moment Closure (CMC) model (Klimenko & Bilger (1999)), or the compositional pdf model (O’Brien (1980), Pope (1985)). In common technical applications, it has be...
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Predictions of scalar mixing and the scalar dissipation rate from large-eddy simulations of a piloted nonpremixed methane/air diffusion flame (Sandia flame D) using the Lagrangian-type flamelet model are presented. The results obtained for the unconditionally filtered scalar dissipation rate are qualitatively compared with general observations of scalar mixing from experiments in non-reactive a...
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In this study a new formulation of the unsteady flamelet model is derived to account for the locally resolved distribution of the scalar dissipation rate obtained from large-eddy simulations (LES). Starting from the unsteady flamelet equations, a transformation leads to an Eulerian flamelet model, in which the scalar dissipation rate appears as function of time, space, and mixture fraction. In ...
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Scalar dissipation rate is an essential parameter in combustion theory; understanding its behavior is necessary for developing and improving combustion models. In most cases, the scalar dissipation rate shows different trends under different combustion conditions, and it is thus case-dependent. Spray combustion is categorized as a partially-premixed combustion system, leading to very complex pr...
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ژورنال
عنوان ژورنال: Proceedings of the Combustion Institute
سال: 2019
ISSN: 1540-7489
DOI: 10.1016/j.proci.2018.06.092