Abstract
The combustion characteristics of freely falling droplets, individually generated by the merging of colliding methanol and alkane droplets, were studied and compared with those for pure methanol and alkanes. The merging of the nominally immiscible methanol and alkanes was manifested in an apparently adhesive, but unmixed manner. An air bubble was trapped at the colliding interfaces where they were adhered, with the trapping favored for head-on or near head-on collision orientations. The trapped air bubble ostensibly induced heterogeneous nucleation of the methanol, being facilitated by the relatively low limit of superheat of methanol. The droplet exploded almost immediately upon ignition, leading to extremely short overall lifetime. Delayed, albeit strong, micro-explosion occurred through homogeneous nucleation of methanol at the contacting interface. The global burning rate was again augmented. In general, micro-explosion was facilitated for high boiling point alkanes such as hexadecane and tetradecane. The co-vaporization of methanol and alkane from their respective hemispherical segments constituting the adhered droplet also led to flame colors that were more bluish than yellowish, indicating the reduction of soot from alkane burning in the presence of methanol vapor. In light of the difficulty of forming stable methanol/oil emulsions, the potential of separate injection of oil and methanol in opposed jet arrangement, in direct-injection engines to facilitate collision was suggested. This is an abstract of a paper presented at the 30th International Symposium on Combustion (Chicago, IL 7/25-30/2004).
Original language | English (US) |
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Pages | 20-21 |
Number of pages | 2 |
State | Published - 2004 |
Event | 30th International Symposium on Combustion, Abstracts of Symposium Papers - Chicago, IL, United States Duration: Jul 25 2004 → Jul 30 2004 |
Other
Other | 30th International Symposium on Combustion, Abstracts of Symposium Papers |
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Country/Territory | United States |
City | Chicago, IL |
Period | 7/25/04 → 7/30/04 |
All Science Journal Classification (ASJC) codes
- General Engineering