Open Access

ABSTRACT

Control of a Diffusion Flame By Polygonal Orifices and External Modulation

Artur Tyliszczak*, Agnieszka Wawrzak

Czestochowa University of Technology, Al. Armii Krajowej 21, 42-201 Czestochowa, Poland.

*Corresponding Author: Artur Tyliszczak. Email: .

The International Conference on Computational & Experimental Engineering and Sciences 2019, 22(4), 196-199. https://doi.org/10.32604/icces.2019.05081

Abstract

Efficiency of combustion processes is related to fuel-oxidizer mixing and interactions between a flame and a flow field. Their control can be achieved by passive and/or active techniques and may lead to considerable improvement in performance of various technological devices. Passive control involves manipulation of the flow by changing shape of the flow domains. Active control relies on manipulation of a flow field by an external forcing. The present study aims to give a deeper insight into the applicability of passive devices combined with active control strategy for mixing enhancement in jet type flames. We apply the passive control approach for a geometrically simple problem in which a fuel (hydrogen/nitrogen mixture) issues from a shaped nozzle into a hot co-flowing stream. Additionally at the end of the nozzle we add a periodic forcing, which amplifies natural instability mechanisms. At short distance from the outlet the fuel auto-ignites, the flame propagates through the domain and eventually stabilizes as a lifted flame. We analyze how the shape of the nozzle or parameters of the forcing affect these phenomena. The research is performed using Large Eddy Simulation for turbulent flow modelling combined with a Conditional Moment Closure as the combustion model.

---