研究者詳細 - 河原　伸幸

MISC - 河原　伸幸

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Fuel Breakup near Nozzle Exit of Multi-Hole Injector for DISI Engine

Kawahara, N. Tomita, E. Nakayama, T. Sumida, M

18th Internal Combustion Engine Symposium (International) 2005年

Local stoichiometry measurement of CH4/Air and C3H8/Air laminar flames by LIBS

Ikeda, Y. Nishiyama, A., *Kawahara, N. Tomita, E. Kurahashi, T

Pacifichem 2005 2005年

Highly spatially resolved time evolution of laser-induced air plasma spectrum

Kawahara, N. Tomita, E. Nakayama, T. Kurahashi, T. Ikeda, Y. Nishiyama, A

Pacifichem 2005 2005年

LDV/PDAの基礎と応用

河原伸幸

機械の研究 Vol.57, No.9, pp.937-944. ( 9 ) 937 - 944 2005年

超音波浮揚における液滴近傍音響流のPIV計測

河原伸幸, 冨田栄二

微粒化 2005年

In-spark-plug sensor for analyzing the initial flame and its structure in an SI engine

Yuji Ikeda, Atsushi Nishiyama, Nobuyuki Kawahara, Eiji Tomita, Shigeyuki Arimoto, Akira Takeuchi

SAE Technical Papers 2005年

記述言語：英語

An in-spark-plug flame sensor was developed to measure local chemiluminescence near the spark gap in a practical spark-ignition (SI) engine in order to study the development of the initial flame kernel, flame front structure, transient phenomena, and the correlation between the initial flame kernel structure and cyclic variation in the flame front structure, which influences engine performance directly. The sensor consists of a commercial instrumented spark plug with small Cassegrain optics and an optical fiber. The small Cassegrain optics were developed to measure the local chemiluminescence intensity profile and temporal history of OH*, CH*, and C 2* at the flame front formed in a turbulent premixed flame in an SI engine. A highresolution monochromator with an intensified chargecoupled device (ICCD) and spectroscopy using optical filters and photomultiplier tubes (PMTs) were used to measure the time-series of the three radicals, as well as the in-cylinder pressure. Measurements were made at different engine speeds in an unmodified 223-cc practical SI engine fueled with gasoline. Stable data were obtained over several hours with little noise, and were of the same quality as data from a small M5-type sensor installed instead of a pressure transducer. The relationships between the radical intensities and indicated mean effective pressure (IMEP) were examined and typical cyclic variation was measured at speeds over 7,000 rpm. The behavior of the initial flame was followed from its arrival at the measurement point. The arrival time was faster and IMEP was larger at stoichiometry than under other air/fuel (A/F) conditions. Copyright © 2005 SAE International.

DOI： 10.4271/2005-01-0644

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Liquid Sheet Break-up of High-Pressure Swirl Injector for DISI Engine(Spray Technologies, Atomization)

Kawahara Nobuyuki, Tomita Eiji, Kasahara Daisuke, Sumida Mamoru

The ... international symposium on diagnostics and modeling of combustion in internal combustion engines 2004 ( 6 ) 279 - 285 2004年8月

記述言語：英語出版者・発行元：一般社団法人日本機械学会

Experimental investigations of fuel breakup very close to nozzle of practical high-pressure swirl injector, which is used in direct injection spark ignition (DISI) engine, were carried out. In DISI engines, fuel is directly injected into cylinder therefore the spray characteristics and mixture formation are of primary importance. Many experimental investigations using several measurement techniques like laser sheet method with high-speed camera, LIF or PDA have been carried out for better understandings of spray and combustion characteristics. However, experimental investigations of atomization process were restricted due to very high-speed and very small region phenomena. Although scale-up models have been used to study the primary spray structure, it is impossible to match Reynolds, Weber, and cavitation numbers and time scales in practical high-pressure swirl injector. Microscopic investigation of primary spray structure of practical swirl injector is needed. On the other hand, numerical simulations have been conducted for better understanding of spray formation process. These researches indicated qualitatively good agreement, but the initial conditions, such as liquid sheet thickness and break-up length, were not accurately since break-up process of the liquid sheet from swirl injector has not been examined. In numerical simulation of spray behavior, a sub-model for atomization phenomena is very important. Therefore the primary atomization process and the break-up process of liquid sheet play an important role. In this research, visualizations of primary spray formation process were demonstrated using a high-speed video camera (maximum speed: Imfps) with a long-distance microscope. Initial state and development of the spray were discussed under the different ambient (back) pressure condition. During the injection period, the length and thickness of the liquid sheet, which is produced from the nozzle exit, were measured using Ar-ion laser sheet and high-speed camera. Moreover, fluctuations of the length and thickness of liquid sheet were discussed. Three main conclusions were drawn from this study. (1) It has been shown that the liquid fuel column without swirl motion was injected as a compact jet at the beginning of the injection. During the injection period, the spray indicates the quasi-steady state mode. (2) Liquid film sheet has a ligament structure. Using Ar-ion laser sheet and high-speed camera, length and thickness of the liquid sheet can be measured. (3) Surface waves of liquid sheet can be recognized. Higher ambient (back) pressure makes shorter wavelength of surface waves of liquid sheet of swirl injector.

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密閉燃焼室内における噴霧火炎と周囲空気導入(エンジンシステムII)

冨田栄二, 今橋武, 河原伸幸, 木本泰造

講演論文集 2004 ( 42 ) 241 - 242 2004年3月

PIV Measurement of High-Pressure Swirl Injector Spray near Nozzle Exit for DISI Engine

Kawahara, N. Tomita, E. Fukuda, D. Sumida, M

7th International Congress on Optical Particle Characterization, 2004年

Fuel breakup near nozzle exit of high-pressure swirl injector for gasoline direct injection engine

Nobuyuki Kawahara, Eiji Tomita, Daisuke Kasahara, Takashi Nakayama, Mamoru Sumida

SAE Technical Papers 2004年

記述言語：英語

Experimental investigations of fuel breakup very close to nozzle of practical high-pressure swirl injector, which is used in gasoline direct injection (GDI) engine, were carried out. In GDI engines, fuel is directly injected into cylinder therefore the spray characteristics and mixture formation are of primary importance. In this research, visualizations of primary spray formation process were demonstrated using a high-speed video camera (maximum speed: 1Mfps) with a long-distance microscope. Initial state and development of the spray were discussed under the different injection pressure condition. During the injection period, the length and thickness of the liquid sheet, which is produced from the nozzle exit, were measured using Ar-ion laser sheet and high-speed camera. Primary spray structure and behavior of liquid sheet, especially surface wave of liquid sheet, at nozzle exit were discussed using obtained images. Three main conclusions were drawn from this study. (1) It has been shown that the liquid fuel column without swirl motion was injected as a compact jet at the beginning of the injection. During the injection period, the spray indicates the quasi-steady state mode. (2) Liquid film sheet has a ligament structure. Using Ar-ion laser sheet and high-speed camera, length and thickness of the liquid sheet can be measured. Higher injection pressure causes thinner thickness and shorter length of liquid sheet. (3) Surface waves of liquid sheet can be recognized. Higher injection pressure makes larger wavelength of surface waves of liquid sheet of swirl injector. Copyright © 2004 SAE International.

DOI： 10.4271/2004-01-0542

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3.392μm赤外吸収法を用いたエンジンシリンダ内点火栓近傍炭化水素系燃料濃度計測－実用機関への適用－

冨田栄二, 河原伸幸, 西山淳, 重永真宏

日本機械学会論文集 (B編), 70 ( 690 ) 518 - 524 2004年

記述言語：日本語

An infrared absorption method was used to determine the fuel concentration with a 3.392 μm He-Ne laser. The effects of pressure and temperature on the molar absorption coefficients of hydrocarbon fuels were clarified, so that it increased with increasing temperature and decreased with increasing pressure. Molar absorption coefficient of multi-component fuel like gasoline can be estimated using molar absorption coefficient of each component and considering mass balance. By exchanging an ordinary spark-plug for & spark-plug with a developed sensor in which light can pass through mixture in the combustion chamber, successive measurement of fuel concentration was performed in a spark-ignition engine. The effects of liquid droplets, mechanical vibration, and other gas like H2O on measurement accuracy were discussed.

DOI： 10.1299/kikaib.70.518

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3.392μm赤外吸収法を用いたエンジンシリンダ内点火栓近傍炭化水素系燃料濃度計測－メタン〜空気均一予混合気による検討－

冨田栄二, 河原伸幸, 重永真宏, 西山淳

日本機械学会論文集 (B編), 70 ( 690 ) 511 - 517 2004年

記述言語：日本語

A fiber optic system linked to the optical sensor installed in the spark plug, in which light can pass through the combustion chamber, was developed to determine the fuel concentration near the spark-plug successively using an infrared absorption method. A He-Ne laser with a wavelength of 3.392 μm that coincides with the absorption line of hydrocarbons was used as a light source. By exchanging an ordinary spark plug into this spark plug with the optical sensor, sucessive measurement of fuel concentration before the spark timing near the spark-plug was performed in a spark-ignition engine inducted with homogeneously mixed method methane-air. The fuel concentration was determined from law of Lambert-Beer in consideration for the effects of pressure and temperature on molar absorption coefficient of methane.

DOI： 10.1299/kikaib.70.511

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Development of Combustion Facility of Constant-Volume Vessel for Investigating Combustion Characteristics of Banker Fuel Oil

Tomita, E., *Kawahara, N. Ohuchi, T. Imahashi, T. Takasu, I. Morinaka, H. Yokota, K

24th CIMAC World Congress 2004, 2004年

Combustion Characteristics and Performance of Supercharged Single Cylinder Natural Gas Engine Ignited with Pilot Injection of Diesel Fuel

Tomita, E., *Kawahara, N. Kinoshita, Y. Komoda, T. Sakane, A

FISITA 2004, 2004年

Homogeneous Charge Compression Ignition Combustion with Dimethyl Ether (Effect of Stratified Fuel Concentration)

Kawahara, N. Tomita, E. Arimoto, S

FISITA 2004, 2004年

Time-series A/F Analysis in a SI Engine by Micro-Local Chemiluminescence Technique

Ikeda, Y., *Kawahara, N. Tomita, E

Proc. of 6th COMODIA 2004, 2004 ( 6 ) 455 - 462 2004年

記述言語：英語出版者・発行元：一般社団法人日本機械学会

A small flame sensor was developed to measure the local chemiluminescence intensity of OH*, CH* and 2* in a four-stroke spark-ignition engine in order to understand flame front characteristics, flame propagation speed and local air/fuel (A/F) ratios. This sensor was installed where a pressure transducer was located. The dimensions of the sensor were those of the M5 type; the specifications of the developed small Cassegrain optics were the same as those used in previous engine measurements. The measurements were carried out at engine speeds of 600 and 1200 rpm using propane and gasoline fuels with no hardware modification in a 374.7 cc. model engine. Two types of Cassegrain optics were examined to measure local chemiluminescence of the flame in the engine. The small optics developed can provide very stable data for an experiment lasting several hours, which is sufficient to conduct practical combustion diagnostics. The measurements results with propane and gasoline demonstrated that this sensor is little influenced by fuel type, and the flame propagation speed was similar under both conditions. Although the sensor must be calibrated for a particular engine initially, it can measure local A/F and flame parameters in each cycle in practical engines. On-board diagnostics can be performed using this sensor and the flame speed and local equivalence ratio at the flame front can be calculated without modifying the engine hardware. This sensor should prove useful for measuring flame structure and stoichiometry in order to reduce cyclic variation and give the optimum control of each cylinder in practical engines.

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Liquid Sheet Break-up of High-Pressure Swirl Injector for DISI Engines

Kawahara, N. Tomita, E. Kasahara, D. Sumida, M

Proc. of 6th COMODIA 2004, 2004年

Temperature Measurements of Laminar Propane/Air Premixed Flame using Detailed OH* Spectra Intensity Ratio

Y. Ikeda, T. Kurahashi, *N. Kawahara, E. Tomita

12th Int. Symp. on Application of Laser Techniques on Fluid Mechanics, 2004年

Measurement of Unburned Gas Temperature in an SI Engine Using Fiber-Optic Laser Interferometry

Kawahara, N. Tomita, E. Takasu, K. Goto, K

12th Int. Symp. on Application of Laser Techniques on Fluid Mechanics, 2004年