The mathematical modelling of turbulent flames is a difficult task due to the intense coupling between turbulent transport processes and chemical kinetics. The model presented within this paper is focused on the turbulence-chemistry interaction. The topic of this study is the numerical simulation of turbulent non-premixed hydrogen flame with different turbulent models in order to invest gate their predictive capability. The two turbulent models are compared: the (k-ε) model with a limited Pope's correction and the Reynolds stress model (RSM). The predictions are validated against experimental data provided by Raman and laser Doppler anemometry (LDA) measurements for a turbulent jet hydrogen-air diffusion flame. The turbulence-chemistry interaction is handled with flame let approach. Simulations of test cases with simple geometries verify the developed model and compare favourably with results of earlier investigations that employed both (k-ε) and RSM closures with the CMC and PDF approaches [5,7].

In this present study, the numerical simulations are performed for an axisymmetric turbulent jet diffusion hydrogen/air flame, by using a hybrid Finite-Volume/Composition PDF-Transport method. This method represents a rational approach for the study of turbulent reacting flows containing signficant turbulencechemistry interactions. The major attraction of Composition PDF method is that the terms associated with chemical reaction appear in closed form, leaving only molecular mixing and turbulent transport terms to be modeled. The accuracy of Composition PDF model calculations depends on the accurate representation of the chemistry and on the mixing model including the value of the mixing-model constant CΦ (mixing-model constant CΦ is the mechanical to scalar time scale ratio (CΦ =τt/τΦ).There has been considerable development in the past three decades in PDF methods, and reviews can be found in Dopazo and O'Brien