論文 - 石野　洋二郎

Manipulation of Large-Scale Vortical Structures and Mixing in a Coaxial Jet with Miniature Jet Actuators Toward Active Combustion Control 査読あり 国際誌

Yu Saiki, Shigehiro Tanaka, Shunnya Hattori, Kasumi Nakura, Yojiro Ishino

Flow Turbulence and Combustion   97 ( 4 )   1127 - 1145   2016年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer  

Schlieren 3D-CT Measurement of Instantaneous Density Distributions of the Shock-cell Structure of Under-expanded Supersonic Micro-jet 査読あり 国際共著 国際誌

Ahmad Zaid NAZARI, Yojiro ISHINO, Yuta ISHIKO, Yoshiaki MIYAZATO, Shinichiro NAKAO

Prodeedings of 2016 Asia-Pacific International Symposium on Aerospace Technology   1 - 9   2016年10月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Measurement of instantaneous density distribution of the shock-cell structure of an underexpanded supersonic microjet escaping into an ambient space from an axisymmetric convergent-divergent (Laval) micro nozzle has been conducted. For 3D observation of supersonic microjet, non-scanning 3D-CT technique using a multi-directional quantitative schlieren system with flash light source is employed. In this technique, for simultaneous schlieren photography, the custom-made 20-directional schlieren camera has been constructed and used. This study examines underexpanded supersonic jet from a micro nozzle with nozzle pressure ratio (NPR) 5.0 and plenum chamber pressure (stagnation pressure) 0.505 MPa. This micro nozzle design Mach number is Md = 1.5 and has circular cross-section with an exit diameter of 1000μm. First, the report deals with the density distribution. The density contour plot data of the jet flow is obtained by 3D-CT (Three Dimensional Computer Tomography) reconstruction of the images by MLEM an appropriate CT algorithm. Next, the density distribution data is calculated by formula. Theoretical results based on the theory of Tam (1984) are found to compare favorably with experimental measurement. The measured and calculated results are in acceptable agreement.

Development and Fundamental Study on a Novel Rotational Internal Combustion Engine with a Single-Lobe Peritrochoid Rotor 査読あり 国際誌

Yojiro Ishino, Yu Sakai, Tomoya Niwa, Masato Kumano

Prodeedings of 2016 Asia-Pacific International Symposium on Aerospace Technology   1 - 12   2016年10月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

A novel rotational internal combustion engine is invented and investigated for APU(Auxiliary power unit) of aircrafts and range-extender-power-unit for electric automobiles. For the applications, IC engines are required vibration-free characteristics. In the present engine, no reciprocating component is used, resulting in vibration-free operation. This engine mainly consists of a rotor casing, a rotor and a crank shaft. The rotor shapes as single lobe peritrochoid (S.L.P.) curve. The rotor rotates by the crank shaft of eccentricity e and rotates itself in counter-direction by phasing gears. The rotor casing shape having two cavities is defined as envelope curve of the rotating single-lobe peritrochoid rotor. The room between the rotor and casing performs the working processes for working gas; intake, compression, ignition, expansion and exhaust processes. The intake of premixed gas of air and fuel and exhaust of burnt gas are controlled by rotary valves installed on the combustion recesses of the rotor-casing. The combustion recesses are equipped with spark-electrodes for ignition. One of advantages of this engine compared with Wankel rotary engines and a previous engine invented by authors, is easy and reliable sealing of working gas. In this engine configuration, that is, a sealing component is only installed on waist section of rotor-casing, instead of complex sealing system on a rotor in case of Wankel engines, resulting in high efficiency by low-leakage of working gas.
In this paper, first, configuration and geometries of this engine are described. Next the prototype engine is introduced and the cyclic behavior of the working process of this prototype engine is explained. Performance of the prototype engine driven by an electric motor is also shown.


Rainbow Schlieren Measurements in Underexpanded Jets from Axisymmetric 査読あり 国際誌

Hikaru FUKUDA, Hiroaki MAEDA, Daisuke ONO，Shinichiro NAKAO, Yoshiaki MIYAZATO, Yojiro ISHINO

Proceedings of The 27th International Symposium on Transport Phenomena(ISTP-27)   ISTP27 ( 158 )   1 - 7   2016年09月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

The rainbow schlieren deflectometry is applied for the slightly underexpanded jet issued from an axisymmetric supersonic micro nozzle with a design Mach number of 1.5. The nozzle was designed by the axisymmetric method of characteristics to provide uniform and parallel flow at the nozzle exit and it has inner diameters of 922 m and 1000 m at the nozzle throat and the exit, respectively, and a longitudinal length of 1300 m from throat to exit. The experiment was performed at a nozzle pressure ratio of 4.0 and a throat Reynolds number of 5.84 x 104. The jet density field is reconstructed by the image analysis based upon the Abel inversion of experimental data. The density contour map on the cross-section including the jet centerline is displayed to observe the gross features of micro supersonic jets. The vortex-sheet model on the shock cell structure proposed by Tam is used for a quantitative comparison between experiment and theory.

Schlieren 3D-CT Reconstruction of Instantaneous Ddensity Distributions of Spark-Ignited Flame Kerness of Fuel-Rich Propane-Air Premixture 査読あり 国際誌

Yojiro Ishino, Naoki Hayashi, Yuta Ishiko, Ahmad Zaid Nazari

Proceedings of the ASME 2016 Summer Heat Transfer Conference   HT2016   7423   2016年07月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ASME  

For 3D observation of high speed flames, non-scanning 3D-CT technique using a multi-directional quantitative schlieren system with flash light source, is proposed for instantaneous density distribution of unsteady premixed flames. This "Schlieren 3D-CT" is based on (i)simultaneous acquisition of flash-light schlieren images taken from numerous directions, and (ii) 3D-CT reconstruction of the images by an appropriate CT algorithm. In this technique, for simultaneous schlieren photography, the custom-made 20-directional schlieren camera has been constructed and used. This camera consists of 20 optical systems of single-directional quantitative schlieren system. Each system is composed of two convex achromatic lenses of 50 mm in diameter and 300 mm in focal length, a light source unit, a schlieren stop of a vertical knife edge and a digital camera. The light unit has a flash (9 micro-sec duration) light source of a uniform luminance rectangular area of 1 mm x 1 mm. Both of the uniformity of the luminosity and the definite shape are essential for a quantitative schlieren observation. Sensitivity of the digital cameras are calibrated with a stepped neutral density filter. Target flames are located at the center of the camera. The image set of 20 directional schlieren images are processed as follows. First the schlieren picture brightness is shifted by no-flame-schlieren picture brightness in order to obtain the real schlieren brightness images. Second, brightness of these images is scaled by Gladstone-Dale constant of air. Finally, the scaled brightness is horizontally integrated to form "density thickness images", which can be used for CT reconstruction of density distribution. The density thickness images are used for CT reconstruction by MLEM (maximum likelihood-expectation maximization) CT-algorithm to obtain the 3D reconstruction of instantaneous density distribution. In this investigation, the "density thickness" projection images of 400(H) x 500(V) pixel (32.0 mm x 40.0 mm) are used for 3D-CT reconstruction to produce 3D data of 400(x) x 400(y) x 500(z) pixel (32.0 mm x 32.0 mm x 40.0 mm). The voxel size is 0.08 mm each direction. In this investigation, the target flame is spark-ignited flame kernels. The flame kernels are made by spark ignition for a fuel-rich propane-air premixed gas. First, laminar flow is selected as the premixed gas flow to establish the spherically expanding laminar flame. The CT reconstruction result show the spherical shape of flame kernel with a pair of deep wrinkles. The wrinkle is considered to be caused by spark electrodes. Next turbulent flows behind turbulence promoting grid is selected. The corrugated shape flame kernel is obtained. The schlieren 3D-CT measurements are made for the complicated kernels. CT results expresses the instantaneous 3D turbulent flame kernel shapes.

3D-CT(Computer Tomography) Measurement of an Instantaneous Density Distribution of Turbulent Flames with a Multi-directional Quantitative Schlieren Camera (Reconstructions of High-speed Premixed Burner Flames with Different Flow Velocities) 招待あり 査読あり 国際誌

Yojiro Ishino, Naoki Hayashi, Ili Fatimah Bt Abd Razak, Takahiro Kato, Yudai Kurimoto, Yu Saiki

Flow, Turbulence and Combustion   96 ( 3 )   819 - 835   2016年04月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

In order to provide a suitable technique for 3D observation of high speed turbulent flames, non-scanning 3D-CT(Computer Tomography) technique using a multi-directional quantitative schlieren system with flash light source, is proposed for instantaneous density distribution of unsteady premixed flames. This "schlieren 3D-CT" is based on (i)simultaneous acquisition of flash-light schlieren images taken from numerous directions, and (ii) 3D-CT reconstruction of the images by an appropriate CT algorithm. In this paper, first, as a preliminary research, 3D-CT reconstruction of non-axisymmetric steady flame is made with a single-directional quantitative schlieren system. Next, with custom-made 20 directional schlieren camera, instantaneous density distributions of a high-speed turbulent flames of nozzle exit velocities of 8.0 and 10.0 m/s has been CT-reconstructed. The 3D-views of the reconstructed flame front shape clearly give the information of the flame structure with fine scale corrugations. Based on the distributions, area-enlargement rates of the flame front area are derived, and investigated.

3D Printing of Instantaneous Turbulent Flame Shapes, Experimentally Captured by 3D-Computer Tomography and Multi-Directional Schlieren Photography 招待あり 査読あり 国際誌

Yojiro Ishino, Naoki Hayashi, Yuta Ishiko, Ili Fatimah Bt Abd Razak, Yu Saiki, Kimihiro Nagase, Kazuma Kakimoto

Transactions of ASME, J. Heat Transfer   138 ( 2 )   020912-1   2016年02月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Society of Mechanical Engineeres  

Non-scanning 3D-CT(Computer Tomography) technique employing a multi-directional quantitative schlieren photographic system(top-left picture) with flash light source, has been performed to obtain instantaneous density distributions of high-speed turbulent flames(for reference, the target flame of 8 m/s exit velocity is indicated in the right-top picture). For simultaneous schlieren photography, the custom-made 20-directional schlieren camera was constructed and used. The target turbulent flame is high-speed flames, anchored on the burner of a nozzle exit of 4.2 mm diameter. The image set of 20 directional schlieren images are processed by MLEM CT-algorithm to obtain the 3D reconstruction of instantaneous density distribution. The solid models(bottom picture) of threshold density level of 0.7 kg/m3 are 3D-printed as 4 times large size for detail observations. The average exit velocity of the propane-air mixture of equivalence ratio of 1.1 is set to be 10, 8, 6 and 4 m/s (models from left to right in the bottom picture). The solid models show the complicated shape of the high speed turbulent flames. The flame structure of higher speed flame has fine scale corrugations. This corresponds to the “corrugated flamelets regime” of the Borghi & Peters diagram well.

DOI： 10.1115/1.4032256

Manipulation of large-scale vortical structures and mixing in a coaxial jet with miniature jet actuators 査読あり 国際誌

Y. Saiki, S. Tanaka, S. Hattori, K. Nakura, Yojiro Ishino

8th International Symposium on Turbulence, Heat and Mass Transfer (THMT'15)   2015年09月

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

3D-CT Measurement of Instantaneous Density Distributions of High-Speed Premixed Turbulent Burner Flames with a Multi-Directional Schlieren Camera (Effects of Flow Velocity on 3D Flame Front Shape) 査読あり

Yojiro Ishino, Naoki Hayashi, Ili Fatimah Bt Abd Razak, Yu Saiki

Proceedings of the 1st Thermal and Fluid Engineering Summer Conference, American Society of Thermal and Fluids Engineering   TFESC ( 12970 )   1 - 11   2015年08月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

In present study, in order to provide a suitable technique for 3D observation of high speed turbulent flames, non-scanning 3D-CT technique using a multi-directional quantitative schlieren system with flash light source, is proposed for instantaneous density distribution of unsteady premixed flames. This "Schlieren 3D-CT" is based on (i)simultaneous acquisition of flash-light schlieren images taken from numerous directions, and (ii) 3D-CT reconstruction of the images by an appropriate CT algorithm. For simultaneous schlieren photography, in this experiment, the custom-made 20-directional schlieren camera has been constructed and used. Target flames are located at the center of the camera. The image set of 20 directional schlieren images are processed by MLEM CT-algorithm to obtain the 3D reconstruction of instantaneous density distribution. In this investigation, the target turbulent flame is high-speed burner flames. The burner has a nozzle exit of 4.2 mm diameter. The average flow velocity of the propane-air mixture of equivalence ratio of 1.1 is set to be 4, 6, 8 and 10 m/s. The burner is equipped with a turbulence promoting orifice in the burner tube. In order to anchor the high-speed flame on the burner nozzle, the burner tip has 4 holes for introducing the pilot flames. Results of the 3D-reconstructions indicates that the distributions show the complicated shape of the high speed turbulent flames. It is also found that the flame structure of higher speed flame has fine scale corrugations. This corresponds to the "corrugated flamelets regime" of the Borghi & Peters diagram for premixed turbulent combustion well.

3D Printing of Instantaneous Turbulnet Flame Shapes, Experimentally Captured by 3D-Computer Tomography and Multi-Directional Schlieren Photography 査読あり

Yojiro Ishino, Naoki Hayashi, Yuta Ishiko, Ili Fatimah Bt Abd Razak, Yu Saiki, Kimihiro Nagase, Kazuma Kakimoto

Proceedings of the 1st Thermal and Fluid Engineering Summer Conference   1 - 1   2015年08月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

3D-CT Measurement of an Instantaneous Density Distribution of a Turbulent Premixed Flame with a Multi-Directional Quantitative Schlieren Camera 査読あり

Yojiro Ishino, Takahiro Kato, Yudai Kurimoto, Yu Saiki

Proceedings of 10th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements   2014年09月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

２０方向から同時撮影可能な定量シュリーレンカメラを設計製作し，それを用いて，吹き出し速度10m/sの高速乱流予混合火炎の密度分布のCT（コンピュータ断層造影）再構成を実施した．その結果，当該火炎の複雑な瞬間構造の三次元データの獲得に成功した．

Fundamental Design of a Rotational I.C. Engine "Ishino Engine" with no Eccentric Rotational Component 査読あり

Keisuke TESHIMA, Yusaku YAMAMOTO, Hiroyuki FUJII, Yu SAIKI, Yojiro ISHINO

Proceedings of the 2013 Asia-Pacific International Symposium on Aerospace Technology   2013年11月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

ミニチュア噴流アクチュエータによるメタン・空気同軸噴流の混合および燃焼の能動制御 査読あり

齋木悠，田中繁弘，服部駿也，石野洋二郎

日本機械学会論文集（B 編）   79 ( 807 )   2013年11月

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

Development of an Novel Non-eccentric Rotational Engine "Ishino Engine"(Fundamental Configuration and Characteristics) 査読あり

Yojiro Ishino, Keisuke Teshima, Hiroyuki Fujii, Yusaku Yamamoto, Yu Saiki

Proceedings of the 19th Small Engine Technology Conference   2013年10月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

3D-CT Measurement of Premixed Flames Using a Multi-Directional Quantitative Schlieren Optical System (Solo-Measurement of Density and Combined-Measurement of Density and Light-Emission distributions) 査読あり

Yojiro ISHINO, Kenta HORIMOTO, Takahiro KATO, Shoma ISHIGURO, Yu SAIKI

Procedia Engineering   2013年10月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

非偏心回転式容積形内燃機関の研究（機関構成・原理と作動特性） 査読あり

石野 洋二郎，手嶋 啓介，藤井 博之，山本 優作，齋木 悠

日本機械学会論文集（B編）   79 ( 805 )   1805 - 1815   2013年09月

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担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

3D-CT Measurement of Three-Dimensional Density Distribution of Premixed Flames Using a Multi-Directional Quantitative Schlieren Optical System 査読あり

Y.Ishino,K.Horimoto,T.Kato,S.Ishiguro,Y.Saiki

Proceedings of the 7th Asian-Pacific Conference on Aerospace Technology and Science   2013年05月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

A Novel Non-eccentric Rotation I.C. Engine "Ishino Engine" (Fundamental Configuration and Combustion Process) 査読あり

Y.Ishino,K.Teshima,Y.Yamamoto,H.Fujii,Y.Saiki

Proceedings of the 9th Asia-Pacific Conference on Combustion   2013年05月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Multi-Directional Quantitative Schlieren Observations for 3D-CT Reconstruction of Three-Dimensional Density Distribution of Steady Non-axisymmetric Premixed Flame 査読あり

Y.Ishino,K.Teshima,Y.Yamamoto,H.Fujii, Y.Saiki

Proceedings of the 9th Asia-Pacific Conference on Combustion   2013年05月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

4D-CT Measurement of a Turbulent Premixed Flame by Simultaneous Multi-Directional High-Speed Photography with Multi-Mirror Optical Capture System 査読あり

Yojiro Ishino, Yuya Okita, Yu Saiki, Tahiro Mizokami

Proceedings of The International Symposium on EcoTopia Science’11   2011年12月

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）