Laminar burning velocity measurements of iso-octane + air mixtures at higher unburnt mixture temperatures. (15th March 2021)

• Record Type: Journal Article
• Authors: Kumar, Rohit; Singhal, Aditya; Kumar, Sudarshan
• Is Part Of: Fuel. Volume 288(2021)
• Publication Date: 2021-03-15
• Subjects: Iso-octane + air mixture -- Surrogate fuels -- Laminar burning velocity -- Higher mixture temperature -- Temperature exponent; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2020.119652
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: Burning velocity of iso-octane + air mixtures measured at elevated temperatures. Burning velocity and temperature exponent reported for equivalence range (0.6–1.4). Reaction pathway study compares burning velocities at 470 and 640 K temperatures. Role of CH3 radical in auto-ignition investigated for slightly rich mixtures. Abstract: Surrogate fuels offer an effective and efficient alternative in predicting the combustion characteristics of various practical fuels such as gasoline, kerosene and diesel. Once standardized, the chosen constituents of the surrogate fuels help reduce the complexity involved in the development of detailed kinetic models for engine simulations at global scales. In this study, with air being the oxidizer, iso-octane as a surrogate constituent of the gasoline fuel is used for measuring the laminar burning velocities at high mixture temperatures. Present investigations report LBV measurements for a temperature range of 300–640 K using an externally heated diverging channel (EHDC) method. The comparison is then carried out with the available experimental data in the literature and kinetic model predictions at 1 atm pressure for an equivalence ratio range of ϕ = 0.7–1.4. Temperature exponent, (α) is derived using the power-law correlation and a good consistency is observed between the current measurements and the kinetic model predictions of LLNL-V3 (2008) and Hasse (2000) for a temperature ratio of 1.7 and 1.8 respectively. Reaction pathway analysis exhibits that the presence of species TC3 H6 CHO at 470 K leads to a lower LBV than at 640 K. Methyl radical, CH3 plays a significant role in the auto-ignition phenomena as highlighted from the sensitivity analysis at ϕ = 1.1. The present study also becomes vital in terms of improving the detailed kinetic models targeting the prediction of knocking propensity.