Ignition experiment of a fuel droplet in high-pressure high-temperature ambient

Ryota Nakanishi, Hideaki Kobayashi, Shinichiro Kato, Takashi Niioka

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)

Abstract

In order to obtain the ignition behavior at supercritical pressures, ignition times of a single fuel dropletwere measured in high-pressure high-temperature ambient. A suspended droplet of n-hexadecane or n-heptane with a diameter of 0.35-1.4 mm was quickly immersed in an electric furnace with a temperature up to 950 K. Attachment of the droplet, movement of the furnace, and ignition measurement were carried out in an air vessel with pressures up to 3 MPa. At low pressures, ignition times of both fuels decreased with the initial droplet diameter and thenincreased. Therefore, the ignition time variation with the initial droplet diameter has a minimum. This phenomenon, however, disappeared at high pressures. Also, the ignitable limit of droplet diameter, below which the droplet vaporized completely before ignition, decreased as pressure increased. In the case of a droplet burning at high pressures, the preceding experiment showed that the burning rate constant increased and had a maximum around the critical pressure of fuel. This is significantly caused by variable properties around the critical point such as thermal conductivity and diffusion coefficient; and therefore, the present ignition time was expected to show similar characteristics due to the same reason. Ignition time, however, decreased monotonously with pressure, and even at supercritical pressures, the ignition time behavior did not change much. Being different from the case of combustion, it is suggested that drastic changes of properties did not take place in ignition processes.

Original languageEnglish
Pages (from-to)447-453
Number of pages7
JournalSymposium (International) on Combustion
Volume25
Issue number1
DOIs
Publication statusPublished - 1994

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Fuel Technology
  • Energy Engineering and Power Technology
  • Mechanical Engineering
  • Physical and Theoretical Chemistry
  • Fluid Flow and Transfer Processes

Fingerprint Dive into the research topics of 'Ignition experiment of a fuel droplet in high-pressure high-temperature ambient'. Together they form a unique fingerprint.

Cite this