A fundamental investigation into the relationship between lubricant composition and fuel ignition quality

Handle URI:
http://hdl.handle.net/10754/594070
Title:
A fundamental investigation into the relationship between lubricant composition and fuel ignition quality
Authors:
Kuti, Olawole Abiola; Yang, Seung Yeon ( 0000-0003-4512-8713 ) ; Hourani, Nadim ( 0000-0003-4272-5395 ) ; Naser, Nimal ( 0000-0002-2740-2179 ) ; Roberts, William L. ( 0000-0003-1999-2831 ) ; Chung, Suk-Ho ( 0000-0001-8782-312X ) ; Sarathy, Mani ( 0000-0002-3975-6206 )
Abstract:
A fundamental experiment involving the use of an ignition quality tester (IQT) was carried out to elucidate the effects of lubricant oil composition which could lead to low speed pre-ignition (LSPI) processes in direct injection spark ignition (DISI) engines. Prior to the IQT tests, lubricant base oils were analyzed using ultra-high resolution mass spectrometry to reveal their molecular composition. High molecular-weight hydrocarbons such as nC16H34, nC17H36, and nC18H38 were selected as surrogates of lubricant base oil constituents, and then mixed with iso-octane (iC8H18-gasoline surrogate) in proportions of 1 vol.% (iC8H18 = 99 vol.%) and 10 vol.% (iC8H18 = 90 vol.%) for the IQT experiments. In addition, lubricant base oils such as SN100 (Group I) and HC4 and HC6 (Group III) and a fully formulated lubricant (SAE 20W50) were mixed with iso-octane in the same proportions. The IQT results were conducted at an ambient pressure of 15 bar and a temperature range of 680-873 K. In the temperature range of 710-850 K, the addition of 10 vol.% base oils surrogates, base oils, and lubricating oil to the 90 vol.% iC8H18 reduces the average total ignition delay time by up to 54% for all mixtures, while the addition of 1 vol.% to 99 vol.% iC8H18 yielded a 7% reduction within the same temperature range. The shorter total ignition delay was attributed to the higher reactivity of the lubricant base oil constituents in the fuel mixtures. A correlation between reactivity of base oils and their molecular composition was tentatively established. These results suggest that the lubricants have the propensity of initiating LSPI in DISI engines. Furthermore, similar results for n-alkanes, lubricant base oils, and fully formulated commercial lubricants suggest that it is the hydrocarbon fraction that contributes primarily to enhanced reactivity, and not the inorganic or organometallic additives. © 2015 Elsevier Ltd. All rights reserved.
KAUST Department:
Clean Combustion Research Center
Citation:
Kuti OA, Yang SY, Hourani N, Naser N, Roberts WL, et al. (2015) A fundamental investigation into the relationship between lubricant composition and fuel ignition quality. Fuel 160: 605–613. Available: http://dx.doi.org/10.1016/j.fuel.2015.08.026.
Publisher:
Elsevier BV
Journal:
Fuel
Issue Date:
Nov-2015
DOI:
10.1016/j.fuel.2015.08.026
Type:
Article
ISSN:
0016-2361
Appears in Collections:
Articles; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorKuti, Olawole Abiolaen
dc.contributor.authorYang, Seung Yeonen
dc.contributor.authorHourani, Nadimen
dc.contributor.authorNaser, Nimalen
dc.contributor.authorRoberts, William L.en
dc.contributor.authorChung, Suk-Hoen
dc.contributor.authorSarathy, Manien
dc.date.accessioned2016-01-19T13:20:50Zen
dc.date.available2016-01-19T13:20:50Zen
dc.date.issued2015-11en
dc.identifier.citationKuti OA, Yang SY, Hourani N, Naser N, Roberts WL, et al. (2015) A fundamental investigation into the relationship between lubricant composition and fuel ignition quality. Fuel 160: 605–613. Available: http://dx.doi.org/10.1016/j.fuel.2015.08.026.en
dc.identifier.issn0016-2361en
dc.identifier.doi10.1016/j.fuel.2015.08.026en
dc.identifier.urihttp://hdl.handle.net/10754/594070en
dc.description.abstractA fundamental experiment involving the use of an ignition quality tester (IQT) was carried out to elucidate the effects of lubricant oil composition which could lead to low speed pre-ignition (LSPI) processes in direct injection spark ignition (DISI) engines. Prior to the IQT tests, lubricant base oils were analyzed using ultra-high resolution mass spectrometry to reveal their molecular composition. High molecular-weight hydrocarbons such as nC16H34, nC17H36, and nC18H38 were selected as surrogates of lubricant base oil constituents, and then mixed with iso-octane (iC8H18-gasoline surrogate) in proportions of 1 vol.% (iC8H18 = 99 vol.%) and 10 vol.% (iC8H18 = 90 vol.%) for the IQT experiments. In addition, lubricant base oils such as SN100 (Group I) and HC4 and HC6 (Group III) and a fully formulated lubricant (SAE 20W50) were mixed with iso-octane in the same proportions. The IQT results were conducted at an ambient pressure of 15 bar and a temperature range of 680-873 K. In the temperature range of 710-850 K, the addition of 10 vol.% base oils surrogates, base oils, and lubricating oil to the 90 vol.% iC8H18 reduces the average total ignition delay time by up to 54% for all mixtures, while the addition of 1 vol.% to 99 vol.% iC8H18 yielded a 7% reduction within the same temperature range. The shorter total ignition delay was attributed to the higher reactivity of the lubricant base oil constituents in the fuel mixtures. A correlation between reactivity of base oils and their molecular composition was tentatively established. These results suggest that the lubricants have the propensity of initiating LSPI in DISI engines. Furthermore, similar results for n-alkanes, lubricant base oils, and fully formulated commercial lubricants suggest that it is the hydrocarbon fraction that contributes primarily to enhanced reactivity, and not the inorganic or organometallic additives. © 2015 Elsevier Ltd. All rights reserved.en
dc.publisherElsevier BVen
dc.subjectDirect injection spark ignition (DISI)en
dc.subjectIgnition quality tester (IQT)en
dc.subjectiso-octaneen
dc.subjectLow speed pre-ignition (LSPI)en
dc.subjectLubricant base oilsen
dc.subjectTotal ignition delayen
dc.titleA fundamental investigation into the relationship between lubricant composition and fuel ignition qualityen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.identifier.journalFuelen
kaust.authorKuti, Olawoleen
kaust.authorYang, Seung Yeonen
kaust.authorHourani, Nadimen
kaust.authorNaser, Nimalen
kaust.authorRoberts, William L.en
kaust.authorChung, Suk-Hoen
kaust.authorSarathy, Manien
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