Cyclic variations of diesel sprays

• Published in: Fuel (Guildford) Vol. 68; no. 12; pp. 1558 - 1564
• Main Authors: Yule, A.J., Aval, S.M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.1989; Elsevier
• Subjects: Applied sciences; diesel; Energy; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; ignition; internal combustion engines; Internal combustion engines: gazoline engine, diesel engines, etc; Mechanical engineering. Machine design; sprays; diesel; ignition; sprays; Photography; Turbulence; Penetration; Spraying; Variations; Diesel engine; Fuel injection; Performance; Shadowscopy
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/0016-2361(89)90294-9

The spray pulses produced by a single hole diesel injector were investigated and the cyclic variations, from pulse to pulse, of spray penetration rate were quantified. These variations were found to be significant, with a 10% standard deviation of spray tip penetration velocity, at any downstream position, being typical. Cyclic variations of the nozzle exit velocity, due to the characteristics of the internal flow in the nozzle and the pump, were also investigated. These variations have a standard deviation < 2%. From these and other data it was concluded that the principal causes of cyclic variations are rooted in a lack of repetition of the atomization process, from pulse to pulse. This variation in the atomization or break-up process is a natural phenomenon although nozzle turbulence may increase the effect. The influences of these variations on engine performance and their control are discussed.