A comparison study on the combustion and sooting characteristics of base engine oil and n-dodecane in laminar diffusion flames. (25th July 2019)

• Record Type: Journal Article
• Authors: Wang, Hu; Li, Yixuan; Iqbal, Zohaib; Wang, Yang; Ma, Chunshan; Yao, Mingfa
• Is Part Of: Applied thermal engineering. Volume 158(2019)
• Publication Date: 2019-07-25
• Subjects: LaminarSMOKE -- Engine oil -- Dodecane -- Soot; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2019.113812
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Sooting tendencies of n -dodecane and base engine oil were compared experimentally. The LaminarSMOKE code was adopted to simulate the PAHs' formations. Reaction mechanism of n -dodecane was revised to simulate combustion of engine oil. Formation of PAH species in engine oil flames were analyzed. Abstract: With the introduction of more strict emission legislations and advanced engine technologies, the contribution of engine oil to soot emissions from engines becomes more and more significant. In order to understand the sooting tendency of engine oil, experiments and chemical kinetic analysis were performed on a laminar diffusion flame of the base engine oil, together with a similar n -dodecane flame for comparison. Distributions of polycyclic aromatic hydrocarbon (PAH) and soot in the flames were measured using the method of laser-induced fluorescence and two-color planar laser induced incandescence respectively in the two flames. A reduced n -dodecane-PAH mechanism was adopted to simulate the PAHs' formations in the n -dodecane flame with the laminarSMOKE code. To simulate the four-ring aromatic species (A4), a precursor of soot in simulations, in the base engine oil flame, the reaction rate of a formation reaction of the A4 species, A2R5 + C4 H2 => A4, was enhanced by 3.6 times to better predict the PAH formation process of base oil. With this modification, the n -dodecane-PAH mechanism can well predict the A4 species in the base engine oil flames. Based on the experimental measurements and numerical simulations, the laminar diffusion flames of n -dodecane and base engine oil were analyzed and compared.