Skip to Main content Skip to Navigation
Journal articles

Effect of methane on pilot-fuel auto-ignition in dual-fuel engines

Abstract : The ignition behavior of n-dodecane micro-pilot spray in a lean-premixed methane/air charge was investigated in an optically accessible Rapid Compression-Expansion Machine at dual-fuel engine-like pressure/temperature conditions. The pilot fuel was admitted using a coaxial single-hole 100 µm injector mounted on the cylinder periphery. Optical diagnostics include combined high-speed CH2O-PLIF (10 kHz) and Schlieren (80 kHz) imaging for detection of the first-stage ignition, and simultaneous high-speed OH* chemiluminescence (40 kHz) imaging for high-temperature ignition. The aim of this study is to enhance the fundamental understanding of the interaction of methane with the auto-ignition process of short pilot-fuel injections. Addition of methane into the air charge considerably prolongs ignition delay of the pilot spray with an increasing effect at lower temperatures and with higher methane/air equivalence ratios. The temporal separation of the first CH2O detection and high-temperature ignition was found almost constant regardless of methane content. This was interpreted as methane mostly deferring the cool-flame reactivity. In order to understand the underlying mechanisms of this interaction, experimental investigations were complemented with 1D-flamelet simulations using detailed chemistry, confirming the chemical influence of methane deferring the reactivity in the pilot-fuel lean mixtures. This shifts the onset of first-stage reactivity towards the fuel-richer conditions. Consequently, the onset of the turbulent cool-flame is delayed, leading to an overall increased high-temperature ignition delay. Overall, the study reveals a complex interplay between entrainment, low T and high T chemistry and micro-mixing for dual-fuel auto-ignition processes for which the governing processes were identified
Document type :
Journal articles
Complete list of metadatas

Cited literature [30 references]  Display  Hide  Download

https://hal-ifp.archives-ouvertes.fr/hal-02060812
Contributor : Catherine Belli <>
Submitted on : Thursday, March 7, 2019 - 4:23:47 PM
Last modification on : Tuesday, March 12, 2019 - 1:15:43 AM
Long-term archiving on: : Monday, June 10, 2019 - 4:23:14 PM

File

Effect of Methane on Pillot.pd...
Files produced by the author(s)

Identifiers

Collections

Citation

Aleš Srna, Michele Bolla, Yuri Wright, Kai Herrmann, Rolf Bombach, et al.. Effect of methane on pilot-fuel auto-ignition in dual-fuel engines. Proceedings of the Combustion Institute, Elsevier, 2019, 37 (4), pp.4741-4749. ⟨10.1016/j.proci.2018.06.177⟩. ⟨hal-02060812⟩

Share

Metrics

Record views

67

Files downloads

12