・Spontaneous ignition of droplet pairs

 In addition to the experiment, numerical investigation on the spontaneous ignition behavior of droplet pairs is being conducted in our laboratory. Thereby, the temperature and flow fields which can not be measured in the experiment are quantatively analyzed. Fig. 1 shows the temperature field around the n-heptane droplet during the cool-flame ignition. The cool flame was first obeserved from the left side, which cause the cool-flame igntion on the right side.

Fig. 1 Spontaneous ignition of n-heptane droplet pair(0.1 MPa,700 K)

・Soot modeling

For the development of an eco-friendly engine, understanding of the formation mechanism of soot and PM are highly required. However, soot formation involves not only the chemical reaction in the gas phase but also the dynamics of soot particles, which makes the formation process complex. In our laboratory, MOMIC, a modeling method of soot formation, is used to obtain a knowledge on the formation process from the a variety of fules.

Fig. 2 Growth process of soot