Combustion Visualization of a Supercharged Direct Injection Hydrogen Engine

Kyohei IZUMI (Kawasaki Motors)･Toshitaka FUJIKI (Yamaha Motor)･Yusuke MARUI (Honda Motor)･Yoshinari NINOMIYA (Suzuki Motor)･Kazuki ARIMA･Hiroshi KATO･Taketo MARUBASHI･Yusaku MATSUMOTO･Satoaki ICHI (Kawasaki Motors)

Abnormal combustion that includes preignition and knocking is a big issue in the development of the hydrogen engine for carbon neutrality .
Thus, it is necessary to clarify the peculiar combustion mechanism of hydrogen with visualization.
In this paper, we tried combustion visualization with our supercharged direct injection hydrogen test engine.

Comparison of exhaust NOx, etc. between direct-injection hydrogen engines and intake port injection hydrogen engines

Tomohiko Kamio･Atsushi Yamamoku (Yamaha Motor)･Koichiro Matsushita (Honda)･Kyohei Izumi (Kawasaki Motors)･Yuta Kagawa (Suzuki Motor)

A single-cylinder hydrogen fueled engine was used to compare differences in Nox emissions between port fuel injection (PFI) and direct injection (DI).
NOx emissions in DI varied over a wide range depending on excess air ratio, while PFI produced relatively consistent NOx emissions regardless of engine conditions.
We theorize that this behavior is due to relatively inhomogeneous air-fuel mixing in the case of DI.

Investigation of Effect of Hydrogen Mixture Formation on Hydrogen Combustion by Hydrogen Jet Model

Atsushi Hisano･Yota Sakurai･Masahito Saito (Kawasaki Heavy Industries)･Satoaki Ichi (Kawasaki Motors)

In a hydrogen direct injection engine, the mixing state of hydrogen and air in the cylinder is an important factor to ensure combustion stability. An injector analysis model was constructed from the results of visualization of a hydrogen injection jet using the schlieren method. The effect of injection timing on hydrogen combustion is examined by in-cylinder analysis using the injector analysis model.

Near-infrared two-color pyrometry and numerical investigation on combustion processes of premixed hydrogen-air mixtures in a rapid compression machine

Fangsi Ren･Haoming Gu･Daisuke Kaminuma･Shinji Nakaya･Mitsuhiro Tsue (the University of Tokyo)･Satoaki Ichi (Kawasaki Motors, Ltd.)･Koichiro Matsushita (Honda Motor)･Kishal Saxena (Yamaha Motor)･Yoshinari Ninomiya (Suzuki Motor)

Hydrogen is a promising carbon-neutral alternative fuel for internal combustion engines. In this study, combustion tests of lean and stoichiometric hydrogen-air mixtures were conducted using a rapid compression machine. Flame temperature distribution during the combustion process was measured using high-speed cameras and near-infrared two-color pyrometry. Furthermore, numerical simulations of the combustion process were performed, and the results were compared and validated against experimental data.

Effect of Air Excess Ratio and Engine speed on Instantaneous Heat Flux in Motorcycle Hydrogen Engines

Masakuni Oikawa･Aoshi Yokomori･Yuji Mihara･Yuki Kaga･Takumi Iwata (Tokyo City University)･Tomohiko Kamio･Atsushi Yamamoku (Yamaha Motor)･Kenichi Sano (Honda Motor)･Yoshinari Ninomiya (Suzuki Motor Co., Ltd.)･Michiyasu Owashi (MOTORA,Inc.)

A prototype instantaneous heat flux sensor was attached to the cylinder head of the 125cc motorcycle hydrogen engine with a small displacement and large S/V, and the effects of air excess ratio and rotational speed on the heat flux were confirmed. As a result, the maximum value of instantaneous heat flux increased significantly when the air excess ratio was changed from 2.2 to 1.6 and the engine speed was changed from 3000 rpm to 8000 rpm.