Development of a 1D Combustion Model for Direct Injection Hydrogen Engines Considering Preferential Diffusion

Toshiki Mikami･Hirokazu Kurihara･Yuji Ishii･Kazuhiro Uehara･Hideyuki Handa (Toyota Motor)

This study presents a method for constructing a one-dimensional combustion model for direct injection hydrogen engines using GT-Power. In GT-Power, the equivalence ratio at the flame front is utilized to represent the in-cylinder mixture distribution. In this research, the transition of the equivalence ratio at the flame front is determined by combining calculations from 3D-CFD with actual combustion results from a real engine. Additionally, the parameters for turbulent burning velocity are considered with respect to preferential diffusion. It was confirmed that the constructed model reproduces the combustion characteristics of the real engine well.

Visualizing Hydrogen Jet Concentrations with Negative LIF

Shohei Ishida･Akihiro Ando･Ryusei Tawara (SOKEN)･Shiro Tanno･Jun Miyagawa (Toyota Motor)

Laser-Induced Fluorescence (LIF) is a promising diagnostic technique for measuring the concentration distribution of hydrogen jets with a high signal-to-noise ratio. However, in the case of gaseous fuels, it is difficult to precisely control the vaporization and mixing of the fluorescent tracer, and such fluctuations can adversely affect measurement accuracy. In this study, we applied a background LIF method, in which the tracer is introduced into the ambient environment surrounding the jet, to hydrogen jet flows. By employing image processing, we successfully corrected for variations in tracer concentration, thereby enhancing the reliability of the analysis.

Development of Measurement Method for Equivalence Ratio around the Spark Plug in Spark-Ignition Hydrogen Engine Using M10 Spark Plug

Taisei Bando･Nobuyuki Kawahara･Yoshimitsu Kobashi (Okayama University)･Satoaki Ichi･Kazuki Arima･Hiroshi Kato･Kyohei Izumi (Kawasaki Motors, Ltd.)･Koichiro Matsushita (Honda Motor)･Tomohiko Kamio (Yamaha Motor)･Yoshinari Ninomiya (Suzuki Motor)

The object of this study is to build a SIBS measurement method using an M10 spark plug to measure the equivalence ratio around the spark plug in a Direct-Injection Spark-Ignition Hydrogen Engine. A sapphire window and lateral electrode are attached to the M10 spark plug, and the hydrogen/air mixture ratio is measured using the SIBS method. The equivalence ratio around the spark plug was measured in a Compression-Expansion engine and an actual engine (Engine speed 2000 rpm).

Effect of Excess Air Rate and Injection Timing on Piston Surface Temperature in Cylinder Direct Injection Hydrogen Engines by Temperature Measurement Method Using Multipoint Small Data Logger

Shota Tsukamoto･Masakuni Oikawa･Yuji Mihara･Seiya Yamada･Kentaro Minoda (Tokyo City University)･Masahiko Satou･Toshiyuki Iseki･Junnosuke Yasuda (Komatsu)

One of the challenges of hydrogen engines is the high cooling losses owing to the short flame extinction distance characteristic of hydrogen. In this study, a multipoint small data logger was installed on the piston to measure the temperature distribution on the piston surface, which varied depending on the operating conditions of the direct injection hydrogen engine. As a result, the effects of the air excess rate and injection timing on the piston surface temperature were determined.

Effect of Fuel Supply System on Instantaneous Heat Flux at the Cylinder Liner Wall of Motorcycle Hydrogen Engine

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

Six instantaneous heat flux sensors were installed in the cylinder liner of a 125cc motorcycle hydrogen engine to determine the effect of the injection method and engine speed on the instantaneous heat flux. As a result, the position of the instantaneous heat flux showing the maximum value differed between the premixing method and the direct injection method, and the tendency for the maximum value of the instantaneous heat flux to increase with higher engine speed was identified.

Comparative Verification of Measured and Numerical Analysis Results in Instantaneous Heat Flux of Motorcycle Hydrogen Engine

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

Measurements of instantaneous heat flux at the cylinder head of motorcycle hydrogen engine indicated that the behavior of the instantaneous heat flux varied depending on the excess air ratio and measurement position. Therefore, the heat flux values calculated by the numerical analysis were compared with the measured values to understand the causes of the changing heat flux behavior. In addition, the set values of the numerical analysis based on the measured values are discussed.