iCharacteristics of Trans-Critical Propane Spray Discharged from Multi-Hole GDI Injector

Research output: Contribution to journalArticle

Authors

  • Zhou Zhang
  • Yanfei Li
  • Haichun Ding
  • Zhi Wang
  • Shijin Shuai

External organisations

  • Tsinghua University

Abstract

This paper is to investigate the characteristics of trans-critical propane spray compared with the flash boiling spray ejected from a multi-hole injector in a constant volume chamber by using the Schlieren and backlit imaging methods. The fuel temperature (Tf) is set from 30 °C to 120 °C, injection pressure (pf) from 60 bar to 120 bar and ambient pressure (pa) from 0.2 bar to 10 bar.

The results show that the trans-critical spray has longer vapor penetration and shorter liquid penetration than the flash boiling spray, but those two sprays have similar curve liquid boundaries near the nozzle. Several discernable collapsed shock structures near the nozzle are observed at Tf=120 °C, pf=120 bar, pa=1 bar, but they disappear when pf drops to 60 bar for the transition path may not enter the two-phase region, and the liquid phase hardly occurs. The Mach disk distance of trans-critical spray in this study is larger than that of the under-expanded ideal gas jet because of the collapse phenomenon. At Tf=120 °C, pf=120 bar, the liquid length decreases when paincreases from 0.2 bar to 2.5 bar and increases when pa continues to rise.

Details

Original languageEnglish
JournalExperimental Thermal and Fluid Science
Early online date21 Jul 2018
Publication statusE-pub ahead of print - 21 Jul 2018

Keywords

  • Propane, Trans-critical spray, GDI, Thermodynamic path