Time-Resolved Particle Image Velocimetry of dynamic interactions between hydrogen-enriched methane/air premixed flames and toroidal vortex structures

Abstract

Additional Information:• NOTICE: this is the author's version of a work that was accepted for publication in the International Journal of Hydrogen Energy. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was sub- Regardless of the mixture stoichiometry, the hydrogen substitution to methane leads to a transition from a regime in which the vortex only wrinkles the flame front (x H2 < 0.2) to a * Corresponding author. Phone: +39 0817622673; Fax: +39 0817622915; E-mail address: valeria.disarli@irc.cnr.it 3 more vigorous regime in which the interaction almost results in the separation of small flame pockets from the main front (x H2 > 0.2). This transition was characterised in terms of time histories of flame surface area and burning rate.

Experimental Study of Hydrogen Addition Effects on a Swirl-Stabilized Methane-Air Flame

“…All of the results indicated that the H 2 addition in the fuel stream increased the global chemical reaction rate. In addition, the enhanced reactivity was reported to increase the intensity of interactions between flame-vortex in turbulent flows [13]. The performance of exhaust emissions was an issue of interest in many past studies.…”

Different combustion modes caused by flame-shock interactions in a confined chamber with a perforated plate

“…The present result is in line with the Bychkov theory [25] on flame acceleration mechanism over obstacles. Moreover, Benedetto et al [28][29][30] used time-resolved particle image velocimetry (TRPIV) and large eddy simulation (LES) to investigate the unsteady flame propagation around toroidal vortices generated at the wake of a circular orifice. Their simulation results showed the trend of flame propagation.…”

“…In fact, the flame acceleration and propagation are also the most important stages in the interaction between the flame and shock wave for understanding pressure oscillations. A great deal of effort [25,[28][29][30][31][32] has been spent on studying the turbulent flame acceleration mechanism in channels equipped with and without obstacles in past decades. These studies are focused on the stage of flame acceleration governed by flame-shock interaction which is an efficient way of increasing the flame energy release rate to form the detonation.…”

“…The flame propagation velocity of high hydrocarbon fuels such as gasoline is slow and it is hard to form the shock wave by the flame across the orifice plate under present experimental conditions and the end-gas autoignition does not occur. Thus, we selected a stoichiometric H 2 -air mixture as the test fuel because of its high flame propagation velocity [28,29] and the formation of the obvious shock wave ahead of the flame front, which can be used to investigate the interactions of flame-shock wave. Under certain conditions, the flame-shock interaction can generate end-gas autoignition resulting in strong pressure oscillation which is similar with what occurred in the SI engine.…”

Flame acceleration in pipes containing bends of different angles

“…Many researchers have studied accelerating flames in pipelines, tubes, ducts and other industrial processes (Bauwens et al, 2007;Ciccarell and Dorofeev, 2008;Di Sarli et al, 2012a;Di Sarli et al, 2012b;Di Sarli and Di Benedetto, 2011;Jr. Zipf et al, 2013;Jr.…”