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On Demand Octane Number Enhancement Technology by Aerobic Oxidation

Daicel Corporation-Ichiro Takase, Takamasa Suzuki, Tatsuya Nakano
Honda R&D Co., Ltd.-Kohtaro Hashimoto, Tomohide Kudo, Takuya Sato
Published 2016-10-17 by SAE International in United States
For the purpose of developing onboard gasoline reforming technology for higher octane number fuel on demand, octane number enhancement of gasoline surrogate by aerobic oxidation using N-hydroxyphthalimide catalyst was investigated. At first, octane numbers of the oxygen-containing products from alkane and aromatic compound were estimated using a fuel ignition analyzer. As a result, not only alcohol but also ketones and aldehydes have higher octane numbers than the original alkanes and aromatic compound. Next, gasoline surrogate was oxidized aerobically with N-hydroxyphthalimide derivative catalyst and cobalt catalyst at conditions below 100 °C. As a result, fuel molecules were oxidized to produce alcohols, ketones, aldehydes, and carboxylic acids. N-hydroxyphthalimide derivative catalyst with higher solubility in gasoline surrogate has higher oxidation ability. Furthermore, the estimated octane number of the oxidized gasoline surrogate improves 17 RON. Thus, there is promise in developing and onboard aerobic oxidation reforming process to produce higher octane fuel.
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Study on Cyclic Variations of Laminar Flame Speed in Homogeneous Lean charge Spark Ignition Combustion

Honda R&D Co., Ltd.-Hiroshi Hanabusa, Takashi Kondo, Kohtaro Hashimoto
Nagoya Institute of Technology-Masahiro Furutani
Published 2016-10-17 by SAE International in United States
It is known that lean combustion is effective as one of the ways which improves thermal efficiency of a gasoline engine. In the interest of furthering efficiency, the use of leaner mixtures is desired. However, to realize robust lean combustion it is necessary to reduce combustion cyclic variation while managing the emission nitrogen oxides. In this study, combustion analysis was carried out focusing on cyclic variations of the heat release of lean combustion. Since the initial flame kernel growth speed has a great effect on the indicated mean effective pressure, laminar flame speed (LFS) around the spark plug was analyzed. Infrared absorption spectrophotometry was used for the measurement of a fuel concentration around the spark plug. Moreover, a LFS predicting formula, which can be used in an area leaner than before, was drawn from detailed chemical reaction calculation results, and the LFS around the spark plug was also calculated through the use of this formula. With the presence of high in-cylinder flow or a pre-mixed fuel delivery the LFS variations around the spark plug decreased…
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Effect of Mixture Stratification and Fuel Reactivity on Dual-Fuel Compression Ignition Combustion Process for SI-Based Engine

Honda R&D Co., Ltd.-Kohei Kuzuoka, Junichi Kamio, Kohtaro Hashimoto
Published 2016-10-17 by SAE International in United States
Compression ignition combustion with a lean mixture has high potential in terms of high theoretical thermal efficiency and low NOx emission characteristics due to low combustion temperatures. In particular, a Dual-Fuel concept is proposed to achieve high ignition timing controllability and an extended operation range. This concept controls ignition timing by adjusting the fraction of two fuels with different ignition characteristics. However, a rapid combustion process after initial ignition cannot be avoided due to the homogenous nature of the fuel mixture, because the combustion process depends entirely on the high reaction rate of thermal ignition.In this study, the effect of mixture stratification in the cylinder on the combustion process after ignition based on the Dual-Fuel concept was investigated. Port injection of one fuel creates the homogeneous mixture, while direct injection of the other fuel prepares a stratified mixture in the cylinder at the compression stroke. The difference in equivalence ratio of the stratified mixture and fuel properties of each specific fuel results in sequential ignition. Thus, the heat release rate is lower; in other words,…
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Study on Homogeneous Lean Charge Spark Ignition Combustion

Honda R&D Co., Ltd.-Hiroshi Hanabusa, Takashi Kondo, Kohtaro Hashimoto, Hiroshi Sono
Nagoya Institute of Technology-Masahiro Furutani
Published 2013-10-14 by SAE International in United States
In practical lean burn engines used to date, the use of a stratified air-fuel configuration, with a comparatively rich mixture in the vicinity of the spark plugs, has resulted in the stable combustion of an overall lean mixture. However, because a comparatively rich mixture is burned during the first half of combustion, NOx emissions are not reduced sufficiently.This research focused on a form of lean burn with homogeneous premixture that would be able to balance low NOx emissions with combustion controllability. It is widely known that homogeneous lean premixed gas has poor flame propagation characteristics. To determine the dominant cause of this, this study investigated the combustion properties of a single-cylinder engine while changing the compression ratio and intake temperature. As a result, the primary cause of combustion fluctuation, the abnormal cycle has a low TDC temperature compared to that of other cycles. It was clear that cycles with an unburned gas temperature in TDC below 950 K had particularly poor heat production during the expansion stroke.The effect of the temperature of the unburned mixture…
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Development of Gasoline Combustion Reaction Model

AIST-Kentaro Tsuchiya
Hachinohe National College of Technology-Yoshinori Murakami
Published 2013-04-08 by SAE International in United States
Gasoline includes various kinds of chemical species. Thus, the reaction model of gasoline components that includes the low-temperature oxidation and ignition reaction is necessary to investigate the method to control the combustion process of the gasoline engine. In this study, a gasoline combustion reaction model including n-paraffin, iso-paraffin, olefin, naphthene, alcohol, ether, and aromatic compound was developed.KUCRS (Knowledge-basing Utilities for Complex Reaction Systems) [1] was modified to produce paraffin, olefin, naphthene, alcohol automatically. Also, the toluene reactions of gasoline surrogate model developed by Sakai et al. [2] including toluene, PRF (Primary Reference Fuel), ethanol, and ETBE (Ethyl-tert-butyl-ether) were modified. The universal rule of the reaction mechanisms and rate constants were clarified by using quantum chemical calculation. Then, the heptane, iso-octane, 2,4,4-trimethyl-1-pentene (iso-octene), methylcyclohexane reaction model produced by KUCRS and the toluene, ethanol, and ETBE model were merged to produce gasoline surrogate master model. Chemical species and elementary reactions of the gasoline surrogate master model were reduced by using the Directed Relation Graph (DRG) method to produce 803 chemical species and 3222 reactions.To validate this reduced…
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Development of Gasoline Combustion Reaction Model

Hachinohe National College of Technology-Yoshinori Murakami
Honda R & D-Kohtaro Hashimoto
  • Technical Paper
  • 2012-08-0141
Published 2012-05-23 by Society of Automotive Engineers of Japan in Japan
Gasoline combustion reaction model including n-paraffin, iso-paraffin, olefin, naphthene, alcohol, ether, and aromatic compound was developed. Using quantum chemical calculation, the universal rule of the reaction mechanisms and rate constants were clarified. The model was developed by constructing the automatic generation program of detailed kinetic model and modifying the existing model.
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Development of CFD Model Using RCCE Method for Combustion Simulation

AdvanceSoft-Hitoshi Shiotani
Honda R&D-Hiroyoshi Taniguchi, Kohtaro Hashimoto
  • Technical Paper
  • 2012-08-0201
Published 2012-05-23 by Society of Automotive Engineers of Japan in Japan
A CFD model has been developed for the combustion simulation including a large detailed chemical kinetic mechanism. As substitute for the standard reduction model, the Rate-Controlled Constrained Equilibrium (RCCE) method made it possible to reduce high computational load which is due to the number of species and stiffness. In the present study, we report the computational efficiency and accuracy for the RCCE method incorporated in CFD simulation.
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Inhibition Effect of Ethanol on Homogeneous Charge Compression Ignition of Heptane

Honda R&D Co., Ltd.-Kohtaro Hashimoto
Published 2008-10-06 by SAE International in United States
It is important in the application of bio-ethanol in homogeneous-charge compression ignition (HCCI) engines to investigate the HCCI combustion characteristics of ethanol. As the inhibitory mechanism of ethanol on HCCI combustion is a key factor, simulated chemical reactions are necessary. In this study, chemical reaction simulations in the combustion chamber of a rapid compression machine (RCM) were performed in order to investigate the inhibitory mechanism of ethanol on the HCCI combustion of heptane. The sensitivity analysis results suggested that the OH radical consumption reaction by ethanol that occurs would inhibit the cool flame reaction of heptane. Furthermore, visualization of HCCI combustion with the RCM was conducted using a quartz glass combustion chamber head and ICCD camera. As a result, the cool flame luminescence intensity of heptane was reduced by the addition of ethanol.
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Study on HCCI-SI Combustion Using Fuels Ethanol Containing

Honda R&D Co., Ltd.-Junichi Kamio, Tadashi Kurotani, Kohei Kuzuoka, Yasuyuki Kubo, Hiroyoshi Taniguchi, Kohtaro Hashimoto
Published 2007-10-29 by SAE International in United States
Bio-ethanol is one of the candidates for automotive alternative fuels. For reduction of carbon dioxide emissions, it is important to investigate its optimum combustion procedure. This study has explored effect of ethanol fuels on HCCI-SI hybrid combustion using dual fuel injection (DFI). Steady and transient characteristics of the HCCI-SI hybrid combustion were evaluated using a single cylinder engine and a four-cylinder engine equipped with two port injectors and a direct injector. The experimental results indicated that DFI has the potential for optimizing ignition timing of HCCI combustion and for suppressing knock in SI combustion under fixed compression ratio. The HCCI-SI hybrid combustion using DFI achieved increasing efficiency compared to conventional SI combustion. Feed-forward and feed-back control systems based on DFI enabled the transient operation including acceleration and deceleration during HCCI combustion, re-ignition of HCCI combustion after fuel cut mode, HCCI-SI-HCCI combustion transition, and suppression of knock in SI combustion.
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Effect of Ethanol on the HCCI Combustion

Honda R & D Co., Ltd.-Kohtaro Hashimoto
Published 2007-07-23 by SAE International in United States
Bio-ethanol is one of the most promising alternative fuels for vehicles. It is important for the spread of bio-ethanol to investigate its ignition quality and its optimum combustion procedure. It is particularly important for the application of bio-ethanol to a homogeneous-charge compression ignition (HCCI) engine to investigate the HCCI combustion characteristics of ethanol. In this study, the inhibiting effects of ethanol on the HCCI combustion of heptane were investigated by using a rapid compression machine (RCM) under various conditions. The results indicate that ethanol effectively retarded the hot ignition period of HCCI combustion due to its effective retardation of the cool flame period. The hot ignition peak period for 30 wt% ethanol/70 wt% heptane was more delayed than that of PRF having an octane number of 60 under the ϕ=0.4 condition. In addition, the hot ignition peak period for 50 wt% ethanol/50 wt% heptane was more delayed than that of PRF having an octane number of 80. Furthermore, the effects of diethyl ether, which can be produced from ethanol, on HCCI combustion were investigated by…
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