Primary Reference Fuels (PRFs) as Surrogates for Low Sensitivity Gasoline Fuels
Sajid, Muhammad Bilal
Al Khesho, Issam
Chung, Suk Ho
Roberts, William L.
KAUST DepartmentChemical Engineering Program
Clean Combustion Research Center
Combustion and Laser Diagnostics Laboratory
Combustion and Pyrolysis Chemistry (CPC) Group
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
high-pressure combustion (HPC) Research Group
Permanent link to this recordhttp://hdl.handle.net/10754/618129
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AbstractPrimary Reference Fuels (PRFs) - binary mixtures of n-heptane and iso-octane based on Research Octane Number (RON) - are popular gasoline surrogates for modeling combustion in spark ignition engines. The use of these two component surrogates to represent real gasoline fuels for simulations of HCCI/PCCI engines needs further consideration, as the mode of combustion is very different in these engines (i.e. the combustion process is mainly controlled by the reactivity of the fuel). This study presents an experimental evaluation of PRF surrogates for four real gasoline fuels termed FACE (Fuels for Advanced Combustion Engines) A, C, I, and J in a motored CFR (Cooperative Fuels Research) engine. This approach enables the surrogate mixtures to be evaluated purely from a chemical kinetic perspective. The gasoline fuels considered in this study have very low sensitivities, S (RON-MON), and also exhibit two-stage ignition behavior. The first stage heat release, which is termed Low Temperature Heat Release (LTHR), controls the combustion phasing in this operating mode. As a result, the performance of the PRF surrogates was evaluated by its ability to mimic the low temperature chemical reactivity of the real gasoline fuels. This was achieved by comparing the LTHR from the engine pressure histories. The PRF surrogates were able to consistently reproduce the amount of LTHR, closely match the phasing of LTHR, and the compression ratio for the start of hot ignition of the real gasoline fuels. This suggests that the octane quality of a surrogate fuel is a good indicator of the fuel’s reactivity across low (LTC), negative temperature coefficient (NTC), and high temperature chemical (HTC) reactivity regimes.
CitationBhavani Shankar, V., Sajid, M., Al-Qurashi, K., Atef, N. et al., "Primary Reference Fuels (PRFs) as Surrogates for Low Sensitivity Gasoline Fuels," SAE Technical Paper 2016-01-0748, 2016, doi:10.4271/2016-01-0748.
SponsorsThe authors wish to thank Adrian Ichim for performing the engine experiments. This work was supported by KAUST and the Saudi Aramco FUELCOM program.
JournalSAE Technical Paper Series
Conference/Event nameSAE 2016 World Congress and Exhibition