GDI fuel sprays of light naphtha, PRF95 and gasoline using a piezoelectric injector under different ambient pressures
Type
ArticleKAUST Department
Clean Combustion Research CenterMechanical Engineering Program
Physical Science and Engineering (PSE) Division
high-pressure combustion (HPC) Research Group
Date
2018-03-20Online Publication Date
2018-03-20Print Publication Date
2018-07Permanent link to this record
http://hdl.handle.net/10754/627450
Metadata
Show full item recordAbstract
This study investigates fuel sprays of light naphtha (LN), primary reference fuel (PRF) and gasoline under different ambient pressures with an outwardly opening piezo gasoline direct injection (GDI) fuel injector. The tested gasoline fuel (regular grade with up to 10% ethanol, E10) was obtained by mixing fuels with AKI (the average of the research octane number (RON) and the motor octane number (MON)) of 87 from three local gas stations. Primary reference fuel (PRF) is commonly used as gasoline surrogate fuel and is blended by iso-octane and n-heptane. PRF95 is the blend of 95% iso-octane and 5% n-heptane by volume. LN fuel was provided by Saudi Aramco Oil Company. Five different ambient pressure conditions varied from 1 bar to 10 bar were tested. The spray was visualized by applying a Mie-scattering technique and a high-speed camera was employed to capture the spray images. The spray structure, spray angle, spray penetration length and spray front fluctuation were analyzed and compared among three fuels. Spray images show that a clear filamentary hollow-cone spray structure is formed for all three fuels at atmospheric conditions, and toroidal recirculation vortexes are observed at the downstream spray edges. A higher ambient pressure leads to a stronger vortex located closer to the injector outlet. Generally speaking, larger spray angles are found under higher ambient pressure conditions for all three fuels. Gasoline fuel always has the largest spray angle for each ambient pressure, while PRF95 has the smallest at most time. For each fuel, the spray front penetration length and spray front penetration velocity decrease with increasing ambient pressure. LN, PRF95 and gasoline show similar penetration length and velocity under the tested conditions. A two-stage spray front fluctuation pattern is observed for all three fuels. Stage one begins from the start of the injection and ends at 450–500 μs after the start of the injection trigger (ASOIT) with a slow fluctuation increase for all ambient conditions. After Stage one, the spray front fluctuation increases rapidly to a certain level and then becomes stable in Stage two.Citation
Wu Z, Wang L, Badra JA, Roberts WL, Fang T (2018) GDI fuel sprays of light naphtha, PRF95 and gasoline using a piezoelectric injector under different ambient pressures. Fuel 223: 294–311. Available: http://dx.doi.org/10.1016/j.fuel.2018.03.009.Sponsors
This research was supported in part by the Saudi Aramco Public R&D Center through the Clean Combustion Research Center of the King Abdullah University of Science and Technology under the FUELCOM program. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funding agencies.Publisher
Elsevier BVJournal
FuelAdditional Links
http://www.sciencedirect.com/science/article/pii/S0016236118304009ae974a485f413a2113503eed53cd6c53
10.1016/j.fuel.2018.03.009