Study of non-premixed turbulent flame of hydrogen/air downstream Co-Current injector Mounir Alliche a,* , Salah Chikh b a Laboratoire LMP2M, Universit e de MEDEA, Quartier Ain Dheb, M ed ea, Algeria b USTHB, Facult e de G enie M ecanique & de G enie des Proc ed es, LTPMP, Alger 16111, Algeria article info Article history: Received 11 January 2017 Received in revised form 6 June 2017 Accepted 9 June 2017 Available online xxx Keywords: Non-premixed combustion Turbulent flame CFD Standard K- 3model Hydrogen abstract For three decades, hydrogen has been identified as a versatile potential fuel concurrent to the conventional fuel such as gasoline. In order to fully implement it and to develop the combustion based power devices that may supply much higher energy density, it is very essential to understand the mechanism of Hydrogen/Air combustion. In this work, Computational Fluid Dynamics (CFD) numerical simulations have been performed to study the combustion of non-premixed turbulent hydrogen-air mixture with different equiva- lence ratios and different mass flow rates and its effect on different species formation, peak temperature and NO x formation. The performance of the combustor is evaluated by using FLUENT software under adiabatic wall condition. Generalized finite rate chemistry model was used to analyze the hydrogen-air combustion system. The combustion is modeled using multi-step reaction mechanism with 14 species, until complete conversion of fuel to H 2 O. Through such a systematic analysis, a proper controlled operation condition for the combustor is suggested which may be used as a guideline for combustor design. Results reported in this work illustrate that the CFD simulation can be one of the most powerful, beneficial and economical tool for combustor design and for optimization and performance analysis. They are more sensitive to the model of the transport properties while the reasonable results can be achieved even with the use of global reaction mech- anism and a simple turbulence model as k- ε, which are not excessively time and memory consuming. From an environmental point view, this study shows that the radical pro- duction (OH and NO) is very small although maximum temperature reached exceeded 2000 (K). The mass fraction of NO is much lower if we increase the air inlet velocity, which makes the cold reaction mixture do not promote the NO formation by dissociation. © 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction Over the past three decades, there has been considerable effort in the world to develop and introduce alternative fuels to replace conventional fuels such as gasoline and diesel. Environmental issues, most notably air pollution and limited availability of conventional fuels are among the main moti- vations behind this research for alternative fuels. Thus, if one tries to find a definition of a perfect fuel, hydrogen would probably satisfy most of the desirable characteristics of such a * Corresponding author. E-mail address: alliche_m@yahoo.fr (M. Alliche). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (2017) 1 e9 http://dx.doi.org/10.1016/j.ijhydene.2017.06.081 0360-3199/© 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Alliche M, Chikh S, Study of non-premixed turbulent flame of hydrogen/air downstream Co-Current injector, International Journal of Hydrogen Energy (2017), http://dx.doi.org/10.1016/j.ijhydene.2017.06.081