Effect of unsteady flow field on spray feature in a DISI engine

Tomohiro Ishiguro･shota Minami･Eriko Matsumura･Jirou Senda (Doshisha University)･Shigenori Haraguchi･Yoshihisa Sato (Honda Motor)

In a DISI engine, fuel deposition on the wall is a factor in the formation of PM. In this study, the velocity distribution of the in-cylinder flow field was analyzed using a rapid compression and expansion machine and the spray features during the formation process of spray injected into an unsteady tumble flow field were analyzed by changing the injection pressure and injection timing as parameters.

Development of a Prediction Model of Soot Particle Size Distribution applicable for Design Calculations of Internal Combustion Engines (3rd Report)
-Validation for 5-Component Gasoline Surrogate-

Jun Hashimoto (Oita University)･Kazumasa Ito (Graduate School of Engineering, Oita University)･Tatsuya Kuboyama (Graduate School of Engineering, Chiba University)･Yasuyuki Sakai (Carbon Recycling Energy Research Center, Ibaraki University)･Kazuhiro Akihama (Nihon University)

In previous work, we have proposed a soot prediction model which can predict the soot particle size distribution and is applicable to design calculations of internal combustion engines. The model was validated for experimental results measured by using burner stabilized stagnation flames and a DISI engine for iso-octane/n-heptane/toluene blended fuels. In this study, the model was extended to a 5-component gasoline surrogate, which is composed of iso-octane/n-heptane/toluene/iso-pentane/Trimethylbenzene and reproduces the sooting characteristics of gasoline, and validated against the experimental results of a DISI engine.

Design and simulation of ignition-compression combustion system for gasoline engine

Cong Yao･Wenxin Cai･Yang Song･Gen Chen (Dong Feng Motor)

This article proposes the combustion concept of ignition-compression combustion in principle, and studies it from the aspects of intake port, combustion chamber, piston surface shape, etc. the best ignition-compression combustion system can achieve three-stage heat release in time and zone: Turbulent flame --> Jet flame --> Gentle spontaneous combustion. Then, the influence of boundary simulation analysis on ignition-compression combustion efficiency is analyzed separately from environmental temperature, intake air pressure, ignition advance angle, injection strategy, fuel type, and other factors. The simulation results show that the indicated thermal efficiency of gasoline engine can be 46.9%.

Experimental study of gasoline engine on the test-bench base on SICI combustion model

Wenxin Cai･Cong Yao･Gen Chen･Yang Song (Dong Feng Motor)

This article is based on a new ignition-compression combustion mode, the ignition-compression combustion system was redesigned, and a new ignition-compression combustion mode was verified on the bench. The experimental results showed that the 2 times fuel injection strategy was more suitable for the ignition-compression combustion mode; The timing of secondary injection and excess air coefficient for achieving optimal thermal efficiency are different at different operating points with different speeds and loads; After blending ethanol into fuel, the hydrogen to carbon ratio increases, the fuel's oxidizing properties are enhanced, and the levels of THC, CO, and CO2 emissions decrease.