Investigation of the effect of ignition position on combustion behavior and knock characteristics by using an optically accessible engine

It is generally known that the temperature and mixture concentration in the combustion chamber influence knock intensity. It is assumed that the distribution of temperature and mixture concentration in the end-gas region of a two-stroke engine differs depending on the ignition position. Therefore, t...

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Main Authors: Sota NAKAMURA, Toshiki KIMURA, Kensuke KUWADA, Yosuke ABE, Akihito KASAI, Akira IIJIMA
Format: Article
Language:English
Published: The Japan Society of Mechanical Engineers 2022-07-01
Series:Mechanical Engineering Journal
Subjects:
Online Access:https://www.jstage.jst.go.jp/article/mej/9/4/9_21-00405/_pdf/-char/en
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author Sota NAKAMURA
Toshiki KIMURA
Kensuke KUWADA
Yosuke ABE
Akihito KASAI
Akira IIJIMA
author_facet Sota NAKAMURA
Toshiki KIMURA
Kensuke KUWADA
Yosuke ABE
Akihito KASAI
Akira IIJIMA
author_sort Sota NAKAMURA
collection DOAJ
description It is generally known that the temperature and mixture concentration in the combustion chamber influence knock intensity. It is assumed that the distribution of temperature and mixture concentration in the end-gas region of a two-stroke engine differs depending on the ignition position. Therefore, this study investigated the effect of the ignition position on knock behavior in a spark-ignition engine. A two-stroke air-cooled single-cylinder gasoline test engine was used to investigate autoignition and abnormal combustion behavior based on in-cylinder pressure analysis, in-cylinder visualization of combustion and frequency analysis of in-cylinder pressure waveforms. Six ignition positions were defined, considering the distribution of temperature and gas concentration in the cylinder. The results revealed that the ignition position influenced localized autoignition development behavior and knock intensity owing to the related distribution of temperature and fuel concentration. It was observed that knock was relatively weak when a large quantity of high-temperature residual burned gas was present in the end-gas region because it suppressed a sharp pressure rise. Knock was also relatively weak in the presence of a large quantity of fresh charge in the end-gas region because the flame was able to propagate sufficiently. Strong knock occurred when the fresh charge and residual gas were both present in the end gas-region because the high-temperature residual gas easily autoignited and autoignition developed rapidly in the new charge that readily burned. Accordingly, it was found that conditions tending to induce strong knock were present when a distribution of high-temperature areas conducive to autoignition and a distribution of high fuel concentration conducive to combustion occurred in the end-gas region. In addition, the dominant knock vibration mode was the 1,0 mode regardless of the ignition position, although it was observed that the resonant frequency varied depending on the end-gas distribution.
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spelling doaj.art-2e5f53d0703f40fdb0e262cfba4721582022-12-22T04:11:33ZengThe Japan Society of Mechanical EngineersMechanical Engineering Journal2187-97452022-07-019421-0040521-0040510.1299/mej.21-00405mejInvestigation of the effect of ignition position on combustion behavior and knock characteristics by using an optically accessible engineSota NAKAMURA0Toshiki KIMURA1Kensuke KUWADA2Yosuke ABE3Akihito KASAI4Akira IIJIMA5Department of Mechanical Engineering, Graduate School of Science and Technology, Nihon UniversityDepartment of Mechanical Engineering, Graduate School of Science and Technology, Nihon UniversityDepartment of Mechanical Engineering, Graduate School of Science and Technology, Nihon UniversityDepartment of Mechanical Engineering, Graduate School of Science and Technology, Nihon UniversityHonda R&D Co., Ltd.Department of Mechanical Engineering, College of Science and Technology, Nihon UniversityIt is generally known that the temperature and mixture concentration in the combustion chamber influence knock intensity. It is assumed that the distribution of temperature and mixture concentration in the end-gas region of a two-stroke engine differs depending on the ignition position. Therefore, this study investigated the effect of the ignition position on knock behavior in a spark-ignition engine. A two-stroke air-cooled single-cylinder gasoline test engine was used to investigate autoignition and abnormal combustion behavior based on in-cylinder pressure analysis, in-cylinder visualization of combustion and frequency analysis of in-cylinder pressure waveforms. Six ignition positions were defined, considering the distribution of temperature and gas concentration in the cylinder. The results revealed that the ignition position influenced localized autoignition development behavior and knock intensity owing to the related distribution of temperature and fuel concentration. It was observed that knock was relatively weak when a large quantity of high-temperature residual burned gas was present in the end-gas region because it suppressed a sharp pressure rise. Knock was also relatively weak in the presence of a large quantity of fresh charge in the end-gas region because the flame was able to propagate sufficiently. Strong knock occurred when the fresh charge and residual gas were both present in the end gas-region because the high-temperature residual gas easily autoignited and autoignition developed rapidly in the new charge that readily burned. Accordingly, it was found that conditions tending to induce strong knock were present when a distribution of high-temperature areas conducive to autoignition and a distribution of high fuel concentration conducive to combustion occurred in the end-gas region. In addition, the dominant knock vibration mode was the 1,0 mode regardless of the ignition position, although it was observed that the resonant frequency varied depending on the end-gas distribution.https://www.jstage.jst.go.jp/article/mej/9/4/9_21-00405/_pdf/-char/enknockingautoignitionspark ignition (si)frame visualizationfrequency characteristics
spellingShingle Sota NAKAMURA
Toshiki KIMURA
Kensuke KUWADA
Yosuke ABE
Akihito KASAI
Akira IIJIMA
Investigation of the effect of ignition position on combustion behavior and knock characteristics by using an optically accessible engine
Mechanical Engineering Journal
knocking
autoignition
spark ignition (si)
frame visualization
frequency characteristics
title Investigation of the effect of ignition position on combustion behavior and knock characteristics by using an optically accessible engine
title_full Investigation of the effect of ignition position on combustion behavior and knock characteristics by using an optically accessible engine
title_fullStr Investigation of the effect of ignition position on combustion behavior and knock characteristics by using an optically accessible engine
title_full_unstemmed Investigation of the effect of ignition position on combustion behavior and knock characteristics by using an optically accessible engine
title_short Investigation of the effect of ignition position on combustion behavior and knock characteristics by using an optically accessible engine
title_sort investigation of the effect of ignition position on combustion behavior and knock characteristics by using an optically accessible engine
topic knocking
autoignition
spark ignition (si)
frame visualization
frequency characteristics
url https://www.jstage.jst.go.jp/article/mej/9/4/9_21-00405/_pdf/-char/en
work_keys_str_mv AT sotanakamura investigationoftheeffectofignitionpositiononcombustionbehaviorandknockcharacteristicsbyusinganopticallyaccessibleengine
AT toshikikimura investigationoftheeffectofignitionpositiononcombustionbehaviorandknockcharacteristicsbyusinganopticallyaccessibleengine
AT kensukekuwada investigationoftheeffectofignitionpositiononcombustionbehaviorandknockcharacteristicsbyusinganopticallyaccessibleengine
AT yosukeabe investigationoftheeffectofignitionpositiononcombustionbehaviorandknockcharacteristicsbyusinganopticallyaccessibleengine
AT akihitokasai investigationoftheeffectofignitionpositiononcombustionbehaviorandknockcharacteristicsbyusinganopticallyaccessibleengine
AT akiraiijima investigationoftheeffectofignitionpositiononcombustionbehaviorandknockcharacteristicsbyusinganopticallyaccessibleengine