2134/31842
Ruipengyu [Brandon] Li
Ruipengyu [Brandon]
Li
Weeratunge Malalasekera
Weeratunge
Malalasekera
Salah Ibrahim
Salah
Ibrahim
LES-DFSD modelling of turbulent premixed flames past repeated obstacles
Loughborough University
2018
Turbulent premixed flames
LES
Dynamic flame surface density model
Repeated obstacles
Mechanical Engineering not elsewhere classified
2018-02-15 12:19:50
Conference contribution
https://repository.lboro.ac.uk/articles/conference_contribution/LES-DFSD_modelling_of_turbulent_premixed_flames_past_repeated_obstacles/9554837
This paper presents simulations of propagating turbulent premixed deflagrating flames past built-in solid obstructions in a small-scale combustion chamber. The design of the chamber allows for up to three baffle plates and a central square obstacle to be positioned in the path of the propagating flames in order to generate turbulence and increase the flame propagating speed. The test case considered in this paper uses a stagnant, stoichiometric propane-air mixture in the configuration of three baffles and one central obstacle. Simulations have been carried out with the Large Eddy Simulation (LES) technique. The filtered reaction rate in LES is accounted for using a novel dynamic flame surface density (DFSD) model. Both numerical and experimental results show that the flame is initially laminar and becomes fully turbulent after continuous interaction with the obstacles downstream. Satisfactory agreement made between the LES calculations and the experimental data confirms the capability of the DFSD model in reproducing essential flame characteristic parameters including the maximum overpressure and flame front speed. The interaction between obstacle-generated turbulence and the flame front is quantified using the sub-grid-scale (SGS) wrinkling factor. Various stages of flame propagation and the dynamic behaviours of the flame are also examined based on the evolution and spatial distribution of the wrinkling factor.