Tsuneo Someya, Tomokazu Ohtake, Takeyuki Kamimoto, Michikata Kono and Kei Miwa : Advanced Combustion Science, --- Fuel Pyrolysis and Fuel-Air Mixing in the Diesel Combustion Process ---, Springer-Verlag, Tokyo, Mar. 1993.
Adam Abdullah, Tomonori Gomi, Tomoaki Yatsufusa, Yoshiyuki Kidoguchi and Kei Miwa : Analysis of Droplet Evaporation Process of Diesel Spray during Ignition Delay Period, COMODIA2008, 377-382, 2008.
(要約)
In diesel combustion, spray evaporation and mixture formation during ignition delay period play an important role in ignition, combustion and emission production. Therefore, this study focused on diesel fuel evaporation process during ignition delay period. Two types of shadowgraph photography method were employed in this experiment: single and double nano-spark shadowgraph photography methods. Single nano-spark shadowgraph photography enables us to capture relatively clear still image of evaporating spray including fuel droplets, liquid phase and vapor phase. On the other hand, double nano-spark shadowgraph photography can record the double exposure images of droplets and liquid phase that can measure droplets velocity and their flying direction. Droplets velocity and flying direction have an influence on droplets evaporation and, furthermore, mixture formation processes. Therefore, the velocity vector distribution of the droplets gives suggestive information on mixture formation during ignition delay period. Results show that spray evaporation begins immediately after start of fuel injection under the condition of high ambient temperature, in particular, at the middle of the spray. Spray atomization is fast promoted at this region, leading to ignition. The ambient temperature and injection pressure affect the droplet size and the number of droplets. Furthermore, droplets behavior, in particular flying direction at spray boundary, is strongly affected by the shear stress caused by the ambient temperature and injection pressure.
Yoshiyuki Kidoguchi, Yasutaka Sato, Tomoaki Yatsufusa and Kei Miwa : Development of Diesel Soot Aftertreatment System using Barrier Discharge Plasma and Oxidation Catalyst, COMODIA2008, 745-752, 2008.
(要約)
This study is concerned with an aftertreatment system of diesel soot. The system first causes a non-thermal barrier discharge plasma reaction. Exhaust NO is converted into NO_2 by O_3 and activated oxygen radicals in the atmosphere of the plasma reaction. The produced NO_2 gas is then introduced into soot filter and is used to improve soot oxidation. NO_2 gas has an effect to start soot oxidation at low temperature. Moreover, this study employs a cheap oxidation catalyst made from iron oxides to promote soot oxidation. This paper tries to improve NO conversion into NO_2 and soot oxidation so as to apply the system to an engine. Results show that exhaust gas flow caused by configuration of plasma reactor has a great effect on improving conversion efficiency of NO into NO_2. High turbulence flow activates chemical reaction between NO and plasma gases. Honeycomb filter with wall-flow structure is used for soot oxidation. The iron oxide catalyst is blended about 30% in weight in the structural materials of the honeycomb before manufacturing the filter. The filter with the oxidation catalyst has a great effect on soot oxidation free from CO production with keeping low temperature oxidation of soot.
This study tried to improve ignitability of intermittent CNG jet for gas-fuelled engines. Fundamental experiment was carried out using a constant volume combustion chamber. CNG was directly injected into the combustion chamber by a gas injector and the jet was ignited by a spark plug. The effect of injection control and spark position on ignition and combustion of CNG jet was investigated by high-speed schlieren photography, combustion pressure measurement, and analysis of gas flow employing laser sheet technique and numerical calculation. Results show that ignitability of CNG jet is improved by controlling jet velocity. Ignition near injector at jet boundary is effective to reduce jet velocity, resulting in improvement of ignitability. Multiple injection was applied to CNG jet combustion. At the multiple injection, CNG is ignited after the end of the first injection. The second injection supports the development of initial flame, and CNG is supplied to the flame during the third injection. Multistage injection is effective to reduce initial jet velocity and promote initial flame development, leading to high ignitability of CNG jet with high injection pressure. Moreover, when CNG jet is impinged to the spark plug, jet velocity is further reduced and flame development is also improved, which produces higher ignitability and prevents wall quenching.
Hwa Seong Jun, Yoshiyuki Kidoguchi, Kwon Tae Kim and Kei Miwa : Characteristics of Lifted Flame Resulting from Impulsive Change of Equivalence Ratio, Journal of the Combustion Society of Japan, Vol.50, No.152, 145-151, 2008.
Nakamura Yoshihisa, Yamamoto Kazunari, Nakajima Nobuo, Yoshiyuki Kidoguchi and Kei Miwa : Noble Hydrogen Engine with Knock-less and Low NOx Emission Employing Hydrogen Gas-jet Combustion and Z-crankshaft Mechanism, Transactions of The Society of Automotive Engineers, No.2007-24-0122, 1-9, 2007.
Adam Abdullah, Inukai Naoki, Yoshiyuki Kidoguchi and Kei Miwa : A Study on Droplets Evaporation at Diesel Spray Boundary during Ignition Delay Period, Transactions of The Society of Automotive Engineers, No.2007-01-1893, 1-11, 2007.
Jazair Wira, Harada Toru, Kubo Syunsuke, Yoshiyuki Kidoguchi and Kei Miwa : Improvement of Emission in a DI Diesel Engine Fuelled by Bio-diesel Fuel and Waste Cooking Oil,, Transactions of The Society of Automotive Engineers, No.2007-01-2029, 1-10, 2007.
Experimental work was performed to investigate formation of soot precursor and PM in diesel combustion process using a flow reactor and a laminar co-flow diffusion burner. Thermally decomposed aliphatic diesel fuel produced in the flow reactor was supplied directly to the burner as fuel. Measurements were conducted in the flow reactor, in the flame, and the exhaust for light hydrocarbons, low molecular weight aromatics, PAHs, soot precursor, and PM. Results show that many PAHs ranging from two to five-member ring are already formed as well as light hydrocarbon such as C_2H_4, C_2H_2 and CH_4 during pyrolysis in the flow reactor. Exhaust PM is subject to be formed when abundant C_2H_2, Benzene, PAHs are produced during high temperature thermal decomposition of aliphatic diesel fuel, and the structure of PM has long chain-like aggregation. Measured fluorescence spectrometry indicates 464nm peak. This peak is caused by soot precursor, which is in the SOF extracted from PM.
Noge Hirofumi, Yoshiyuki Kidoguchi and Kei Miwa : A Study on NO Reduction Caused by Thermal Cracking Hydrocarbons during Rich Diesel Combustion, JSME International Journal, Series B: Fluids and Thermal Engineering, Vol.49, No.2, 526-532, 2006.
(要約)
This study tries to investigate the reduction of nitric oxide by thermally cracked hydrocarbons under rich condition during diesel combustion. Experiments using flow reactor system, which follows the chemical process of fuel at high temperature and atmospheric pressure, show that thermal cracking of fuel starts at about 1000K, and lower hydrocarbons mainly composed of C_2H_4 and CH_4 are formed. NO can be reduced when fuel is thermally cracked and oxidized. A larger amount of NO is reduced when thermal cracking hydrocarbons are increased in quantity under rich and high temperature condition. Among decomposed hydrocarbons, C_2H_4 is easily decomposed and affects deNO mechanism. Chemical kinetic calculation using CHEMKIN III reveals the mechanism. NO is reduced through the reaction of HCCO or CH_2 with NO. In these reaction paths, C_2H_2 is an essential species. The computation also shows that this deNO mechanism can be actualized in the practical diesel combustion.
Yoshiyuki Kidoguchi, Kei Miwa and Noge Hirofumi : DeNOxMechanism Caused by Thermal Cracking Hydrocarbons in Stratified Rich Zone during Diesel Combustion, International Journal of ENGINE RESEARCH, Vol.6, No.6, 547-556, 2005.
This study tries to investigate the reduction of nitric oxide by thermally cracked hydrocarbons under rich condition during diesel combustion. Experiments using flow reactor system, which follows the chemical process of fuel at high temperature and atmospheric pressure, show that thermal cracking of fuel starts at about 1000K, and lower hydrocarbons mainly composed of C_2H_4 and CH_4 are formed. NO can be reduced when fuel is thermally cracked and oxidized. A larger amount of NO is reduced when thermal cracking hydrocarbons are increased in quantity under rich and high temperature condition. Among decomposed hydrocarbons, C_2H_4 is easily decomposed and affects deNO mechanism. Chemical kinetic calculation using CHEMKIN III reveals the mechanism. NO is reduced through the reaction of HCCO or CH_2 with NO. In these reaction paths, C_2H_2 is an essential species. The computation also shows that this deNO mechanism can be actualized in the practical diesel combustion.
Suminori Tanaka, Kazunori Nakagawa, Eiji Kanezaki, Masahiro Katoh, Kei-ichiro Murai, Toshihiro Moriga, Ichiro Nakabayashi, Shigeru Sugiyama, Yoshiyuki Kidoguchi and Kei Miwa : Catalytic Activity of Iron Oxides Supported on γ-Al2O3 for Methane Oxidation, Journal of the Japan Petroleum Institute, Vol.48, No.4, 223-228, 2005.
(要約)
Three kinds of catalysts of goethites supported on γ-Al2O3 (Fe/γ-Al2O3), SiO2-Al2O3 (Fe/SiO2-Al2O3) and SiO2 (Fe/SiO2) were investigated in terms of the catalytic activity of methane oxidation. The specific surface areas of these catalysts were larger in common than the area of goethite with no supports. The Fe/γ-Al2O3 catalyst has the highest performance in the low-temperature activity of methane oxidation which started at 623 K and completed at 923 K. When the Fe-content in Fe/γ-Al2O3 was increased, the formation of goethite was observed by the X-ray analyses and the activity of this catalyst increased up to 6 mol%. After the catalytic methane oxidation at 823 K, it was observed that goethite in Fe/γ-Al2O3 transformed to hematite which has been known as an active iron oxide in methane oxidation. The activity of Fe/γ-Al2O3 was enhanced by the addition of sodium up to the Na-content of 5 mol% although it descended above the content due to the decrease of the specific surface area of the catalyst.
(キーワード)
Iron oxide catalyst / Goethite / Hematite catalyst / Alumina support / Methane oxidation / Combustion catalyst
Sung-Sub Kee, Ali Mohammadi, Yoshiyuki Kidoguchi and Kei Miwa : Effects of Aromatic Hydrocarbons on Fuel Decomposition and Oxidation Processes in Diesel Combustion, Transactions of The Society of Automotive Engineers, No.2005-01-2086, 1-8, 2005.
Ali Mohammadi, Yoshinori Kaneda, Takashi Sogo, Yoshiyuki Kidoguchi and Kei Miwa : A Study on Diesel Emission Reduction using a High-frequency Dielectric Barrier Discharge Plasma, SAE Paper, No.2003-01-1879, 1-8, 2003.
Sung-Sub Kee, Ali Mohammadi, Hiroyuki Hirano, Yoshiyuki Kidoguchi and Kei Miwa : Experimental Study on Combustion Characteristics and Emission Reduction of Emulsified Fuels in Diesel Combustion Using a Rapid Compression Machine, SAE Paper, No.2003-01-1792, 1-8, 2003.
Yoshiyuki Kidoguchi, Michiko Sanda and Kei Miwa : Experimental and Theoretical Optimization of Combustion Chamber and Fuel Distribution for the Low Emission Direct-Injection Diesel Engine, Journal of Engineering for Gas Turbines and Power, Vol.125, No.1, 351-357, 2003.
Ali Mohammadi, Yoshiyuki Kidoguchi and Kei Miwa : Effect of Injection Parameters and Wall-Impingement on Atomization and Gas Entrainment Processes in Diesel Sprays, SAE Technical Papers, No.2002-01-0497, 1-10, 2002.
Kei Miwa, Ali Mohammadi and Yoshiyuki Kidoguchi : A Study on Thermal Decomposition of Fuels and NOx Formation in Diesel Combustion using a Total Gas-sampling Technique, International Journal of ENGINE RESEARCH, Vol.2, No.3, 189-198, 2001.
Yoshiyuki Kidoguchi, Kei Miwa and Ali Mohammadi : Reduction Mechanism of NOx in Rich and High Turbulence Diesel Combustion, 5th COMODIA Symposium, Vol.5, No.1, 108-114, 2001.
Yoshiyuki Kidoguchi, Changlin Yang, Ryoji Kato and Kei Miwa : Effects of Fuel cetane number and aromatics on combustion process and emissions of a direct-injection diesel engine, JSAE Review, Vol.21, No.4, 469-475, 2000.
Changlin Yang, Yoshiyuki Kidoguchi, Ryoji Kato and Kei Miwa : Effects of Fuel Properties on Combustion and Emissions of a Direct-Injection Diesel Engine, Bulletin of MESJ, Vol.28, No.2, 55-62, 2000.
Yoshiyuki Kidoguchi, Changlin Yang and Kei Miwa : Effects of Fuel Properties on Combustion and Emission Characteristics of a Direct-Injection Diesel Engine, SAE Paper, Vol.2000, No.01-1851, 1-9, 2000.
Yoshiyuki Kidoguchi, Changlin Yang and Kei Miwa : Effect of High Squish Combustion Chamber on Simultaneous Reduction of NOx and Particulate from a Direct-Injection Diesel Engine, SAE, Vol.1999, No.1999-01-1502, 1-11, 1999.
Changlin Yang, Yoshiyuki Kidoguchi and Kei Miwa : Effect of Rich and High Turbulence Combustion on NOx and Particulate Emissions from a High Speed Direct-Injection Diesel Engine, COMODIA98, Vol.4, 63-68, 1998.
Kei Miwa, Tsunehiro Ohmija and Toshio Nishitani : A Study of the Ignition Delay of Diesel Fuel Spray Using a Rapid Compression Machine, JSME International Journal, Vol.31, No.1, 166-173, 1998.
Ali Mohammadi, Kei Miwa, Takuji Ishiyama and Makoto Abe : Measurement of Droplet Size, Shape and Velocity In Diesel Sprays using a Single and Double Nano-spark Photography Method, JSME International Journal, Series B: Fluids and Thermal Engineering, Vol.41, No.1, 7-12, 1998.
Ali Mohammadi, Kei Miwa, Takuji Ishiyama and Makoto Abe : Investigation of Droplets and Ambient Gas Interaction In a Diesel Spray Using A Nano-Spark Photography Method, SAE Transactions, Vol.107, No.3, 1694-1705, 1998.
Takuji Ishiyama, Kei Miwa and Osamu Horikoshi : A Study on Ignition Process of Diesel Sprays, JSME International Journal, Series B: Fluids and Thermal Engineering, Vol.38, No.3, 483-489, 1995.
Takuji Ishiyama, Kei Miwa and Atsuo Kanno : Experimental Study of Fuel AIR Mixture Formation and Ignition process in Diesel Combustion, Internal Symposium on COMDIA 90, Vol.2, No.90, 565-570, 1990.
Ikegami Makoto, Li Xin-he, Nakayama Yoshihiro and Kei Miwa : Trend and Origins of Particulate and Hydrocarbon Emission from a Direct-Injection Diesel Engine, SAE Transactions, Vol.92, No.3, 815-829, 1984.
Makoto Ikegami, Kei Miwa and Masahiro Shioji : A Study of Hydrogen fuelled Compression Ignition Engines, Int. Journal of Hydrogen Energy, Hydrogen Energy Progress, Vol.7, No.4, 341-353, 1982.
Ikegami Makoto, Kei Miwa and Ikeda Hakuichi : Analyses of the Diesel Combustion Process Based on Varying Delay Mechanism, --- 1st.Report, Theoretical Model and its Verification ---, Bulletin of JSME, Vol.17, No.114, 1619-1628, 1974.
Fujio Nagao, Makoto Ikegami, Kei Miwa, Goki Okazaki, Hisao Sugimato and Takeshi Nanba : Measuremant of Air Flows by Means of Repetitive Spark Method, Bulletin of JSME, Vol.14, No.78, 1340-1351, 1971.
(キーワード)
Internal Combustion Engine / Gas flow / Measumennt method
Shingo Okamoto, Ryota Shibamoto, Yoshiyuki Kidoguchi and Kei Miwa : Effect of High Turbulence Mixing on Reduction of Exhaust Emissions from a DI Diesel Engine Employing EGR and Pilot Injection, The 18th Internal Combustion Engine Symposium (International) in Jeju (Korea), No.63, 1-6, Cheju, Dec. 2005.
2.
Hirofumi Noge, Yuichi Yoshihara, Yoshiyuki Kidoguchi and Kei Miwa : A Study on Formation of Soot Precursor in Diffusion Flame Fueling Decomposed Diesel Fuel, 1st Baltic Combustion Meeting, 33-36, Warsaw, Nov. 2005.
3.
Kei-ichiro Murai, Yuichiro Murakami, Tomiko Sei, Masahiro Katoh, Ichiro Nakabayashi, Toshihiro Moriga, Suminori Tanaka, Yoshiyuki Kidoguchi and Kei Miwa : Total Oxidation of Activated Carbon over PdO-CeO2/TiO2-Al2O3 Catalyst, Advanced Materials Development & Performance Conference 2005, Auckland, Jul. 2005.
4.
Suminori Tanaka, Kohei Tomita, Kazunori Nakagawa, Kei-ichiro Murai, Toshihiro Moriga, Ichiro Nakabayashi, Yoshiyuki Kidoguchi and Kei Miwa : Synthesis and Oxidation Activities of Catalysts Supported Goethite, The 13th International Conference on Processing and Fabrication of Advanced Materials, Singapore, Dec. 2004.
5.
Yoshiyuki Kidoguchi, Kei Miwa and Eiji Goda : Effect of Stratified Rich and High Turbulence Combustion on the Reduction of NOx and Particulate Emissions from a DI Diesel Engine, Proc. of Thermo-and fluid dynamic process in Diesel Engines, 227-235, Valencia, Sep. 2002.
Yoshiyuki Kidoguchi, Michiko Sanda and Kei Miwa : Experimental and Theoretical Optimization of Combustion Chanber and Fuel Distribution for the Low Emission DI Diesel Engine, Proc. of the 2001 Spring Technical Conference of the ASME Internal Combustion Engine Division, Vol.36, No.2, 131-138, Philadelphia, Apr. 2001.
Ali Mohammadi, Kei Miwa and Yoshiyuki Kidoguchi : High Time-Space Resolution Analysis of Droplets Behaviour and Gas Entrainment into Diesel Sprays Impinging on a Wall, 16th Annual Conference on Liquid Atomization and Spray Systems, Vol.16, No.16, 51-56, Germany, Sep. 2000.
Ali Mohammadi, Yoshiyuki Kidoguchi, Kei Miwa and Tomoyuki Hirose : Effect of Diesel Spray Impingement on Fuel-Air Mixing Process In Diesel Engines, Proc. of 15th ICE Symposium, Vol.15, No.15, 127-132, Korea, Jul. 1999.
Seiji Miyashiro, Ali Mohammadi, Kei Miwa and Gronig Hans : Optical Measurement of Liquid Sprays with New Nanosecond Spark Light Source, Flow Visualization, Vol.9, No.9, 981-986, Italy, Sep. 1998.