Spotlights

Surface-energy ratchet mechanism
The proposed ratchet mechanism utilizes the asymmetry in surface wettability between the smooth and rough faces of the teeth of a geometrically symmetric gear to achieve ratcheting motion. .

The research team, including Dr. Dai Matsuda, a former doctoral student, Jiro Senda and Eriko Matsumura, professors at the Faculty of Science and Engineering, revealed the mechanisms behind wall film formation, which is a crucial contributor to particulate matter emissions under cold fuel conditions.

Particulate matter emissions from direct injection engines are a major environmental issue. Matsuda and his colleagues studied how wall films, which form when fuel sprays onto engine walls, contribute to these emissions in cold conditions. They found that cold fuel creates thicker wall films, producing more particulate emissions. This finding will help develop improved fuel injection methods, making engines cleaner and helping to attain the upcoming Euro 7 emission standards.

Reference
Dai MATSUDA, Akira ADACHI, Akari SHIMONO, Eriko MATSUMURA, Jiro SENDA, Experimental analysis of spray impingement wall film at cold temperatures for Direct-Injection spark ignition engines, Fuel, Volume 374, 2024,132407.
https://doi.org/10.1016/j.fuel.2024.132407

For more details, please see the website of Organization for Research Initiatives and Development, Doshisha University.
https://research.doshisha.ac.jp/news/news-detail-59/


This achievement has also been featured in the “EurekAlert!.”
NEWS RELEASE 27-AUG-2024, Analysis of Spray Impingement and Wall Film Formation in Direct Injection Engines.

Credit: "Car exhaust" by eutrophication&hypoxia 
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