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RANS modelling of a lifted hydrogen flame using eulerian/lagrangian approaches with transported PDF method

Author:
Larbi, Ahmed Amine, Bounif, Abdelhamid, Senouci, Mohamed, Gökalp, Iskender, Bouzit, Mohamed
Source:
Energy 2018 v.164 pp. 1242-1256
ISSN:
0360-5442
Subject:
carbon monoxide, chemical reactions, dynamic models, environmental factors, equations, hydrogen, mixing, nitrogen oxides, physical models, prediction, probability, probability distribution, reaction mechanisms, statistical models, temperature, turbulent flow
Abstract:
In this study, the eulerian probability density function approach (EPDF) has been applied to simulate turbulent diffusion flame in a Vitiated Coflow. EPDF is the eulerian method to solve the PDF transport equations with a direct-quadrature-method-of-moments (DQMOM) closure. The PDF transport equation represented by a set of governing equations for the probability of occurrence in any environmental condition and the probability weighted species mass fractions, which are solved in an eulerian solution [1]; it is considered a product of the delta function, in order to model the turbulence–chemistry interaction. Among these advantages are the prediction and the kinetic control of the species such as CO and NOX. Even though the EPDF approach has been improved in recent years, most improvements have been achieved with parametric study in order to investigate the impact of the model accuracy. The main objective of this investigation is the numerical evaluation of the PDF approach accuracy, using different mixing models and turbulence models, to predict the lift-off height, the extinction and ignition of the flame. Another study comparative of eulerian (EPDF) and lagrangian monte-carlo (LPDF) was applied by equivalent physical models and numerical parameters for evaluating the performances of each approach such as precision and computational specification. The chosen mixture model is the IEM (Interaction by Exchange with the Mean) for micro-mixing closure. The number of environment in the eulerian approach EPDF is (2.0). Through the use of a dynamic model for the mixing time-scale, by computing the individual time-scales for the reactive scalars dynamically in each cell during the course of the simulation using the ANSYS-Fluent/MM-INTAS CFD codes and the chemical reaction mechanism injected is GRI mech 2.1. The results such as mixture fraction, temperature, species mass fraction is validated with experimental data and discussed.
Agid:
6161281