Open AccessOn the improvement by laser ignition of the performances of a passenger car gasoline engine
Author(s) -
N. Pavel,
Radu Chiriac,
Adrian Birtas,
Florin Draghici,
Mihai Dinca
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.00a385
Subject(s) - laser ignition , automotive engineering , materials science , ignition timing , spark plug , ignition system , petrol engine , brake specific fuel consumption , mean effective pressure , combustion , lean burn , environmental science , fuel efficiency , internal combustion engine , spark ignition engine , gasoline , four stroke engine , compression ratio , combustion chamber , nox , mechanical engineering , waste management , engineering , chemistry , aerospace engineering , organic chemistry
Laser ignition was used to operate a four-stroke, four-cylinder, multipoint fuel injection gasoline passenger car engine, replacing the engine classical ignition device. The laser ignition system was compactly built with diode end-pumped Nd:YAG/Cr 4+ :YAG composite ceramics, each laser spark plug delivering pulses at 1.06 μm with 4 mJ energy and 0.8 ns duration at variable repetition rate, in accordance with the engine speed. The engine was operated at constant speed-constant load condition of 2000 rpm-2 bar equivalent brake mean effective pressure, and different ignition timings, thus simulating city traffic situations. Two relative air-fuel ratios have been considered: λ~1 for the stoichiometric mixture operation and λ~1.25 for the lean mixture condition. Parameters indicating engine performance, efficiency, combustion stability, and emissions have been measured and registered when groups of 500 consecutive cycles were acquired. The engine brake power, brake specific fuel consumption, coefficient of variability for indicated mean effective pressure, initial and main combustion stage durations, as well as exhaust emissions like carbon monoxide (CO) and total unburned hydrocarbons (THC) emphasized that significant improvements can be obtained for lean air-fuel mixture operation. Increases of the nitrogen oxides emission (NO x ) were measured when laser ignition was used.