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Investigation of H2 Formation Characterization and its Contribution to Post-Oxidation Phenomenon in a Turbocharged DISI Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on September 15, 2020 by SAE International in United States
In this research, a deeply simulative and experimental investigation of H2 emission formation during the post-oxidation phenomenon and its influence were conducted in a turbo-charged spark ignition engine. During the post-oxidation phenomenon phase, rich air-fuel ratio (A/F) is used inside the cylinder and partially fresh air is scavenged to the exhaust manifold which further reacted with unburned gas species in exhaust manifold. This rich excursion gives rise to the production of H2 emission by various reactions inside the cylinder. It is expected that the generation of this H2 emission can play a key role in the actuation of the post-oxidation and its reaction rate if enough temperature and mixing strength are attained. It is predicted that when rich combustion inside the cylinder will take place, more CO/THC/H2 content will arrive in the exhaust manifold. This H2 content facilitates in the production of OH radicals which contributes to the post-oxidation reaction and in-turn can aid towards increasing the enthalpy. Through simulations, it was also investigated that higher H2 levels influences the ignition delay of the post-oxidation reaction significantly. In addition, the H2 formation with different overlap and spatial distribution were also analyzed. It was noted that the H2 formation always came to be higher at high overlap due to better scavenging which makes in-cylinder mixture rich. Also, at the 90 deg. overlap, the H2 concentration firstly increases when we move from exhaust port to TC upstream. This is due to the inhomogeneity that occurred between port to TC upstream. Further as we move from TC upstream to TC downstream, the H2 level decreases due to the consumptions of H2 in post-oxidation reaction. It was also noted that at higher load the H2 emission was lower due to cooling effects that slowed down the chemical reaction.
- Madan KUMAR - Chiba University
- Salaar Moeeni - Chiba University
- Tatsuya Kuboyama - Chiba University
- Yasuo Moriyoshi - Chiba University
- Jan Przewlocki - Universitat Stuttgart - IVK
- Rodolfo Tromellini - Universitat Stuttgart - IVK
- Michael Grill - Universitat Stuttgart (FKFS)
- Marco Chiodi - Universitat Stuttgart (FKFS)
- Michael Bargende - Universitat Stuttgart (FKFS)