Working on development of a new engine
that has not yet been put into practical use

Department of Modern Mechanical and Engineering (CSE Graduate School)
Master’s program 2nd year
Machi Matsutaka
Jin Kusaka Laboratory

Q: Please tell us about your research.

I am working in Professor Kusaka’s laboratory on a joint project with an automobile manufacture for development of an engine that uses a novel combustion system. This is an engine in which combustion takes place by homogeneous charge compression ignition (HCCI).
The engines generally in use today use either gasoline or diesel fuel. The former produces low emissions at the expense of poor fuel efficiency, while the latter provides good fuel efficiency but with a higher level of emissions. The HCCI combustion system combines the advantages of these two systems to resolve the shortcomings of both. A number of companies are conducting research into HCCI engines, and it is expected that they will come into practical use sometime between 2020 and 2030.

Q: What exactly is involved in this type of engine?

Every engine works by igniting a mixture of fuel and air.
In today’s gasoline engines, a pre-mixed combination of fuel and air is ignited by spark plug. The problem with this system is that time is required for combustion to expand spherically through the mixture from the center of ignition, which is the spark plug. This lag is what accounts for the poor fuel efficiency of such engines.
On the other hand, instead of using spark plugs, diesel engines work by super-heating a volume of air through compression with a piston, and then injecting diesel fuel which ignites spontaneously upon injection. This is possible because diesel fuel ignites at relatively low temperature. However, when diesel fuel is injected into the cylinder, variations in density are produced, and soot results from the denser regions.
With the HCCI combustion system, a mixture of gasoline and air is compressed and spontaneous combustion is induced by a chemical reaction, making it possible to optimize fuel efficiency while minimizing environmental consequences. However, it is hard to induce spontaneous combustion in gasoline, which presents a challenge with regard to controlling the timing of ignition.

Doing experiments on actual engines is a lot of fun!

Q: What aspects of your research do you find enjoyable, and which present a challenge?

That would certainly be testing on actual engines. It’s a lot of fun to work with actual engines and observe them running. It is really fulfilling to see a predictive model based on mathematical formulae confirmed in actual operation.
On the other hand, achieving such confirmation is extremely difficult, and getting through the period of trial and error is quite a challenge. Sometimes the expressions on which a model is based don’t produce expected results, even when you redo them after reviewing all the literature.

Q: What made you decide to enter the Department of Modern Mechanical Engineering?

While I was a senior in high school, an earlier graduate of the school who entered the Department of Modern Mechanical Engineering came back for a visit, and he took the opportunity to explain his research to the school’s students. His presentation was very interesting, and that was the actual starting point.
However, I have always liked doing things with my hands, and I participated in woodworking class while I was still in elementary school. Also, my father worked in road service, and maybe it has something to do with the how impressed I was by the way he could repair vehicles.