Air-Entrainment in Wall-Jets Using SLIPI in a Heavy-Duty Diesel Engine

Research output: Contribution to journalArticle

Abstract

Mixing in wall-jets was investigated in an optical heavy-duty diesel engine with several injector configurations and injection pressures. Laser-induced fluorescence (LIF) was employed in non-reacting conditions in order to quantitatively measure local equivalence ratios in colliding wall-jets. A novel laser diagnostic technique, Structured Laser Illumination Planar Imaging (SLIPI), was successfully implemented in an optical engine and permits to differentiate LIF signal from multiply scattered light. It was used to quantitatively measure local equivalence ratio in colliding wall-jets under non-reacting conditions. Mixing phenomena in wall-jets were analyzed by comparing the equivalence ratio in the free part of the jet with that in the recirculation zone where two wall-jets collide. These results were then compared to φ predictions for free-jets. It was found that under the conditions tested, increased injection pressure did not increase mixing in the wall-jets. Comparisons with free-jet predictions further indicated that mixing in wall-jets is less effective than in free-jets for identical conditions and downstream distances. The confined nature of the wall-jet in the optical engine is suspected to be the reason for these observations. A rapid leaning-out of the jet after end of injection was observed for all cases, but this enhanced mixing was not transmitted to the wall-jet.

Details

Authors
Organisations
External organisations
  • Lund University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering
Original languageEnglish
Article number2012-01-1718
Pages (from-to)1684-1692
Number of pages9
JournalSAE International Journal of Engines
Volume5
Issue number4
Publication statusPublished - 2012 Sep 10
Publication categoryResearch
Peer-reviewedYes
EventSAE 2012 International Powertrains, Fuels & Lubricants Meeting - Malmo, Sweden
Duration: 2012 Sep 182012 Sep 20