Structure of igniting ethanol and n-heptane spray flames with and without swirl

• Published in: Experimental thermal and fluid science Vol. 43; pp. 47 - 54
• Main Authors: Letty, Camille, Mastorakos, Epaminondas, Masri, Assaad R., Juddoo, Mrinal, O’Loughlin, William
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier Inc 01.11.2012; Elsevier
• Subjects: Applied sciences; Combustion of liquid fuels; Combustion. Flame; Energy; Energy. Thermal use of fuels; Ethanol; Ethyl alcohol; Evolution; Exact sciences and technology; Fast-response OH-PLIF; Flame structure; High speed; Ignition; Laser ignition; Spark ignition; Spray flames; Sprayers; Sprays; Swirl; Theoretical studies. Data and constants. Metering; Fast-response OH-PLIF; Spark ignition; Laser ignition; Swirl; Spray flames; Spray combustion; Ethanol; Chemiluminescence; Combustion; Experimental study; Heptane; Fluorescence spectrometry; Laser; Flame structure
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2012.03.020

► Spark ignition of swirling flames by laser shows timescales of successful and failed sparks. ► Ethanol and n-heptane flames show different reaction fronts. ► Fast-response OH-PLIF system reveals flame evolution from ignition to complete flame establishment. This paper explores the ignition and subsequent evolution of spray flames in a bluff-body configuration with and without swirl. Ethanol and n-heptane are used to compare the effects of volatility. Ignition is performed by a laser spark. High speed imaging of OH*-chemiluminescence and OH-PLIF collected at 5kHz are used to investigate the behaviour of the flames during the first stages of ignition and the stable flame structure following ignition. Swirl induces a wider and shorter flame, precession, and multiple reaction zones, while the non-swirling flames have a simpler structure. The reaction fronts seem thinner with ethanol than with heptane. The dataset can be used for model validation.