Reinitiation process of detonation wave behind a slit-plate T. Obara; J. Sentanuhady; Y. Tsukada; S. Ohyagi
巻：18,
号：2,
開始ページ：117,
終了ページ：127, 2008年07月
The propagation phenomenon of a detonation wave is particularly interesting, because the detonation wave is composed of a 3D shock wave system accompanied by a reaction front. Thus, the passage of a detonation wave draws cellular patterns on a soot-covered plate. The pressure and temperature behind the detonation wave are extremely high and may cause serious damages around the wave. Therefore, it is of great significance from a safety-engineering point of view to decay the detonation wave with a short distance from the origin. In the present study, experiments using high-speed schlieren photography are conducted in order to investigate the behaviors of the detonation wave diffracting from two slits. The detonation wave produced in a stoichiometric mixture of hydrogen and oxygen is propagated through the slits, and the behaviors behind the slit-plate are investigated experimentally. When a detonation wave diffracts from the slits, a shock wave is decoupled with a reaction front. Since the two shock waves propagate from the slits interact with each other at the center behind the plate, the detonation wave is reinitiated by generating a hot-spot sufficient to cause local explosions. Furthermore, it is clarified that the shock wave reflected from a tube-wall is also capable of reinitiating the detonation wave. The reinitiation distance of the detonation wave from the slit-plate is correlated using a number of cells emerged from each slit.
英語
DOI：https://doi.org/10.1007/s00193-008-0147-9DOI ID：10.1007/s00193-008-0147-9,
ISSN：0938-1287,
Web of Science ID：WOS:000257383600005 酸水素予混合気体への衝撃波入射により生じる燃焼波の伝ぱ形態
小原哲郎; 栗原慶博; 落合俊幸; 大八木重治
日本機械学會論文集. B編, 巻：74, 号：740, 開始ページ：949, 終了ページ：956, 2008年
rights: 社団法人日本機械学会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110006655833/In this paper, experimental results were reported to investigate a behavior of combustion wave when a shock wave was transmitted into a combustible premixed gas of oxygen and hydrogen. In general, phenomena occurring in the premixed gas would be classified into four types, i.e. (a) the shock wave was just transmitted without causing ignition for the shock wave propagated with low-Mach number, (b) the gas was ignited behind the shock wave and a deflagration wave was propagated following the shock wave, (c) the deflagration wave was transited to a detonation wave behind the shock wave, (d) a detonation wave was directly initiated just behind incident shock wave having high-propagation Mach number. In this study, a shock wave produced by a detonation-driven shock tube was transmitted into a premixed gas of oxygen and hydrogen varied with an equivalence ratio, initial pressure of premixed gas and Mach number of the shock wave. As a result, the phenomena of combustion wave were classified using a cell-size of steady-propagating detonation wave. For sensitive gases having small cell-size, the detonation wave was directly initiated behind the shock wave even though the Mach number of the shock wave was relatively low. Empirical equations to evaluate a Mach number and temperature behind shock wave were obtained, which are threshold parameters to cause detonation wave behind transmitted shock wave.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.74.949, ISSN：0387-5016, CiNii Articles ID：110006655833, CiNii Books ID：AN00187441
酸水素予混合気体への衝撃波入射により生じる燃焼波の伝ぱ形態
小原 哲郎; 栗原 慶博; 落合 俊幸; 大八木 重治
日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B, 巻：74, 号：740, 開始ページ：949, 終了ページ：956, 2008年
rights: 社団法人日本機械学会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110006655833/In this paper, experimental results were reported to investigate a behavior of combustion wave when a shock wave was transmitted into a combustible premixed gas of oxygen and hydrogen. In general, phenomena occurring in the premixed gas would be classified into four types, i.e. (a) the shock wave was just transmitted without causing ignition for the shock wave propagated with low-Mach number, (b) the gas was ignited behind the shock wave and a deflagration wave was propagated following the shock wave, (c) the deflagration wave was transited to a detonation wave behind the shock wave, (d) a detonation wave was directly initiated just behind incident shock wave having high-propagation Mach number. In this study, a shock wave produced by a detonation-driven shock tube was transmitted into a premixed gas of oxygen and hydrogen varied with an equivalence ratio, initial pressure of premixed gas and Mach number of the shock wave. As a result, the phenomena of combustion wave were classified using a cell-size of steady-propagating detonation wave. For sensitive gases having small cell-size, the detonation wave was directly initiated behind the shock wave even though the Mach number of the shock wave was relatively low. Empirical equations to evaluate a Mach number and temperature behind shock wave were obtained, which are threshold parameters to cause detonation wave behind transmitted shock wave.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.74.949, ISSN：0387-5016, CiNii Articles ID：110006655833, CiNii Books ID：AN00187441
デトネーション波の消炎および再開始現象の解明
小原哲郎
総合研究機構研究プロジェクト研究成果報告書, 号：5(18年度), 開始ページ：580, 終了ページ：581, 2007年
スリット板背後におけるデトネーション波の再開始過程 (デトネーション波の再開始と消炎過程の可視化)
小原哲郎; 塚田豊; Jayan Sentanuhady; 大八木重治
日本機械学會論文集. B編, 巻：73, 号：735, 開始ページ：2354, 終了ページ：2361, 2007年
rights: 社団法人日本機械学会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110006453745/A propagation of detonation wave shows particularly interesting phenomena, since the detonation wave is constituted from a three-dimensional shock wave system accompanied with a reaction front. Thus, the passage of a detonation wave draws cellular patterns on a soot-covered plate. Pressure and temperature behind the detonation wave are extremely high and have a potential to cause serious damages around it. Therefore, it is necessary from safety engineering point of view to quench the detonation wave with short distance from the origin. In this study, experiments applied high-speed schlieren photography are conducted to investigate behaviors of the detonation wave diffracting from two pieces of slits. The detonation wave produced in a stoichiometric mixture of hydrogen and oxygen is propagated through the slits and behaviors behind slit-plate are experimentally investigated. As a result, when the detonation wave diffracted from the slits, a shock wave is decoupled with a reaction front. Since two shock waves progagated from the slits interact each other at centre behind the plate, the detonation wave is re-initiated by generating a hot-spot enough to cause local explosion. It is also clarified that the shock wave reflected from a tube-wall induces detonation re-initiation.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.73.2354, ISSN：0387-5016, CiNii Articles ID：110006453745, CiNii Books ID：AN00187441
スリット板背後におけるデトネーション波の再開始過程 (スリット板形状の違いによる影響)
Jayan Sentanuhady; 小原哲郎; 塚田豊; 大八木重治
日本機械学會論文集. B編, 巻：73, 号：732, 開始ページ：1737, 終了ページ：1744, 2007年
rights: 社団法人日本機械学会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110006401679/Pressure and temperature behind a detonation wave are extremely high and have a potential to cause serious damages around it. Therefore, it is necessary from safety engineering point of view to decay the detonation wave with short distance from a generation of it. In this study, experiments are conducted in order to investigate behaviors of the detonation wave propagating into two pieces of slits, since the detonation wave might be quenched behind the slits by expansion waves generated at a corner of the slits and this behavior might be applicable to a technique of detonation-arrester. The detonation wave produced in a stoichiometric mixture of hydrogen and oxygen is propagated through the slits and behaviors of it are experimentally investigated by using a technique of pressure measurement, soot track record and high-speed schlieren photography. As a result, when the detonation wave propagated through the slits, a shock wave is decoupled with a reaction front. Two shock waves diffracted from the slits interact each other at center behind the slits, then this shock wave interaction induces a hot-spot enough to cause local explosion. Since, the shock wave is reflected from a tube-wall eventually, the detonation wave is re-initiated by mechanisms of shock-shock interaction or shock-wall interactions.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.73.1737, ISSN：0387-5016, CiNii Articles ID：110006401679, CiNii Books ID：AN00187441
水素 酸素予混合気体への衝撃波入射により誘起される燃焼波の挙動
小原哲郎; 楢原由樹子; 栗原慶博; 大八木重治
日本機械学會論文集. B編, 巻：73, 号：727, 開始ページ：871, 終了ページ：878, 2007年
rights: 社団法人日本機械学会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110006271376/Experiments were conducted in order to investigate a behavior of comcustion wave when a shock wave was propagated into a combustible premixed gas of hydrogen and oxygen. A phenomenon occurring in the premixed gas can be classified into four types, i.e. (a) the shock wave just transmitted into the gas without causing ignition for the shock wave of low-Mach number, (b) the gas was ignited behind the shock wave and a deflagration wave was propagated following the shock wave, (c) the deflagration wave transited to a detonation wave behind the shock wave, (d) a detonation wave was directly initiated just behind incident shock wave of high-Mach number. In this study, a shock wave produced by a detonation-driven shock tube was transmitted into a hydrogen-oxygen premixed gas varied with an equivalence ratio 0, initial pressure p＼ and Mach number of the shock wave Mst. As a result, the phenomena observed in the gas was classified using a cell-size A for steady detonation wave, since the cell-size was inversely proportional to a chemical reaction rate of the gas. For the case of sensitive gases having small cell-size, the detonation wave was directly initiated behind the shock wave even though the Mach number of the shock wave was relatively low. An empirical equation to evaluate a pressure was obtained, which is a threshold pressure to ignite the gas behind incident shock wave.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.73.871, ISSN：0387-5016, CiNii Articles ID：110006271376, CiNii Books ID：AN00187441
パルスデトネーション・エンジン連続作動特性の研究
遠藤慎介; 中込大輔; 吉橋照夫; 小原哲郎; 大八木重治; 村山元
埼玉大学地域共同研究センター紀要, 巻：8, 号：8, 開始ページ：64, 終了ページ：67, 2007年
A Pulse detonation engine (PDE) is an internal combustion engine that generates power due to intermittent detonations. As an air supply method, many researchers used the solenoid valves. However, it is unsuitable for air breathing engines which use air from the atmosphere. Then, for practical use there, the PDE is expected to be equipped with some kind of rotary valves which can induce air intermittently from the atmosphere. Although some researchers reported the results using such valves for the PDE, a detailed study of the continuous operation PDE has not been reported yet, so it is meaningful to examine the behavior and the optimization of the PDE with the rotary valve. For this object, it is experimented to prove a certain, continuous operation of 40Hz by this device. The combustion test was performed for 30, 35, and 40Hz operations. The performance was evaluated by two parameters, i.e., thrust F [N] and impulse per unit area Icycle [Ns/m2]. As a result, a 120 cycle, 3 seconds operation was able to be achieved by 40Hz. The impulse was decreased as the operation frequency increased, although the thrust was slightly increased.
埼玉大学総合研究機構地域共同研究センター産学連携推進部門, 日本語
ISSN：1347-4758, CiNii Articles ID：120001371278, CiNii Books ID：AA11808968
デトネーション波の消炎および再開始現象の解明
小原哲郎
号：5(18年度), 開始ページ：580, 終了ページ：581, 2007年
スリット板背後におけるデトネーション波の再開始過程 : デトネーション波の再開始と消炎過程の可視化
小原 哲郎; 塚田 豊; Sentanuhady Jayan; 大八木 重治
日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B, 巻：73, 号：735, 開始ページ：2354, 終了ページ：2361, 2007年
rights: 社団法人日本機械学会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110006453745/A propagation of detonation wave shows particularly interesting phenomena, since the detonation wave is constituted from a three-dimensional shock wave system accompanied with a reaction front. Thus, the passage of a detonation wave draws cellular patterns on a soot-covered plate. Pressure and temperature behind the detonation wave are extremely high and have a potential to cause serious damages around it. Therefore, it is necessary from safety engineering point of view to quench the detonation wave with short distance from the origin. In this study, experiments applied high-speed schlieren photography are conducted to investigate behaviors of the detonation wave diffracting from two pieces of slits. The detonation wave produced in a stoichiometric mixture of hydrogen and oxygen is propagated through the slits and behaviors behind slit-plate are experimentally investigated. As a result, when the detonation wave diffracted from the slits, a shock wave is decoupled with a reaction front. Since two shock waves progagated from the slits interact each other at centre behind the plate, the detonation wave is re-initiated by generating a hot-spot enough to cause local explosion. It is also clarified that the shock wave reflected from a tube-wall induces detonation re-initiation.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.73.2354, ISSN：0387-5016, CiNii Articles ID：110006453745, CiNii Books ID：AN00187441
スリット板背後におけるデトネーション波の再開始過程 : スリット板形状の違いによる影響
Sentanuhady Jayan; 小原 哲郎; 塚田 豊; 大八木 重治
日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B, 巻：73, 号：732, 開始ページ：1737, 終了ページ：1744, 2007年
rights: 社団法人日本機械学会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110006401679/Pressure and temperature behind a detonation wave are extremely high and have a potential to cause serious damages around it. Therefore, it is necessary from safety engineering point of view to decay the detonation wave with short distance from a generation of it. In this study, experiments are conducted in order to investigate behaviors of the detonation wave propagating into two pieces of slits, since the detonation wave might be quenched behind the slits by expansion waves generated at a corner of the slits and this behavior might be applicable to a technique of detonation-arrester. The detonation wave produced in a stoichiometric mixture of hydrogen and oxygen is propagated through the slits and behaviors of it are experimentally investigated by using a technique of pressure measurement, soot track record and high-speed schlieren photography. As a result, when the detonation wave propagated through the slits, a shock wave is decoupled with a reaction front. Two shock waves diffracted from the slits interact each other at center behind the slits, then this shock wave interaction induces a hot-spot enough to cause local explosion. Since, the shock wave is reflected from a tube-wall eventually, the detonation wave is re-initiated by mechanisms of shock-shock interaction or shock-wall interactions.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.73.1737, ISSN：0387-5016, CiNii Articles ID：110006401679, CiNii Books ID：AN00187441
水素-酸素予混合気体への衝撃波入射により誘起される燃焼波の挙動
小原 哲郎; 楢原 由樹子; 栗原 慶博; 大八木 重治
日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B, 巻：73, 号：727, 開始ページ：871, 終了ページ：878, 2007年
rights: 社団法人日本機械学会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110006271376/Experiments were conducted in order to investigate a behavior of comcustion wave when a shock wave was propagated into a combustible premixed gas of hydrogen and oxygen. A phenomenon occurring in the premixed gas can be classified into four types, i.e. (a) the shock wave just transmitted into the gas without causing ignition for the shock wave of low-Mach number, (b) the gas was ignited behind the shock wave and a deflagration wave was propagated following the shock wave, (c) the deflagration wave transited to a detonation wave behind the shock wave, (d) a detonation wave was directly initiated just behind incident shock wave of high-Mach number. In this study, a shock wave produced by a detonation-driven shock tube was transmitted into a hydrogen-oxygen premixed gas varied with an equivalence ratio 0, initial pressure p＼ and Mach number of the shock wave Mst. As a result, the phenomena observed in the gas was classified using a cell-size A for steady detonation wave, since the cell-size was inversely proportional to a chemical reaction rate of the gas. For the case of sensitive gases having small cell-size, the detonation wave was directly initiated behind the shock wave even though the Mach number of the shock wave was relatively low. An empirical equation to evaluate a pressure was obtained, which is a threshold pressure to ignite the gas behind incident shock wave.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.73.871, ISSN：0387-5016, CiNii Articles ID：110006271376, CiNii Books ID：AN00187441
パルスデトネーション・エンジン連続作動特性の研究
遠藤 慎介; 中込 大輔; 吉橋 照夫; 小原 哲郎; 大八木 重治; 村山 元
埼玉大学地域共同研究センター紀要, 巻：8, 号：8, 開始ページ：64, 終了ページ：67, 2007年
A Pulse detonation engine (PDE) is an internal combustion engine that generates power due to intermittent detonations. As an air supply method, many researchers used the solenoid valves. However, it is unsuitable for air breathing engines which use air from the atmosphere. Then, for practical use there, the PDE is expected to be equipped with some kind of rotary valves which can induce air intermittently from the atmosphere. Although some researchers reported the results using such valves for the PDE, a detailed study of the continuous operation PDE has not been reported yet, so it is meaningful to examine the behavior and the optimization of the PDE with the rotary valve. For this object, it is experimented to prove a certain, continuous operation of 40Hz by this device. The combustion test was performed for 30, 35, and 40Hz operations. The performance was evaluated by two parameters, i.e., thrust F [N] and impulse per unit area Icycle [Ns/m2]. As a result, a 120 cycle, 3 seconds operation was able to be achieved by 40Hz. The impulse was decreased as the operation frequency increased, although the thrust was slightly increased.
埼玉大学総合研究機構地域共同研究センター産学連携推進部門, 日本語
ISSN：1347-4758, CiNii Articles ID：120001371278, CiNii Books ID：AA11808968
Experimental study on the flow field behind a backward-facing step using a detonation-driven shock tunnel TH Kim; T Obara; M Yoshikawa; S Ohyagi
巻：15,
号：1,
開始ページ：1,
終了ページ：12, 2006年03月
The supersonic combustion RAM jet (SCRAM jet) engine is expected to be used in next-generation space planes and hypersonic airliners. To develop the engine, stabilized combustion in a supersonic flow field must be attained even though the residence time of flow is extremely short. A mixing process for breathed air and fuel injected into the supersonic flow field is therefore one of the most important design problems. Because the flow inside the SCRAM jet engine has high enthalpy, an experimental facility is required to produce the high-enthalpy flow field. In this study, a detonation-driven shock tunnel was built to produce a high-enthalpy flow, and a model SCRAM jet engine equipped with a backward-facing step was installed in the test section of the facility to visualize flow fields using a color schlieren technique and high-speed video camera. The fuel was injected perpendicularly to a Mach 3 flow behind the backward-facing step. The height of the step, the injection distance and injection pressure were varied to investigate the effects of the step on air/fuel mixing characteristics. The results show that the recirculation region increases as the fuel injection pressure increases. For injection behind the backward-facing step, mixing efficiency is much higher than with a flat plate. Also, the injection position has a significant influence on the size of the recirculation region generated behind the backward-facing step. The schlieren photograph and pressure histories measured on the bottom wall of the SCRAM jet engine model show that the fuel was ignited behind the step.
英語
DOI：https://doi.org/10.1007/s00193-005-0283-4DOI ID：10.1007/s00193-005-0283-4,
ISSN：0938-1287,
Web of Science ID：WOS:000235759200001 狭い間隙に進入する火炎の挙動に関する実験的研究(熱工学,内燃機関,動力など)
小原哲郎; 大八木重治; 仁科祐介; 成澤伸之
日本機械学會論文集. B編, 巻：72, 号：720, 開始ページ：2018, 終了ページ：2025, 2006年
A behavior of a flame propagating through a narrow channel is of importance, since this phenomenon is concerned with a quenching of the flame when heat losses by convective heat transfer or radiative one to a wall of channel are dominant and temperature behind the flame is not enough to increase that of unburned gases. Since, this phenomenon is also related to a safety-engineering problem where combustible gaseous mixture is handled, a device applying a narrow channel in a pipe might be one of useful technique to prevent the flame from propagating. Experiments were conducted to investigate a behavior of the flame propagating through a narrow channel, which connects two rectangular combustion chambers. The behavior of the flame was visualized using schlieren optical technique with an aid of high-speed video camera. In this study, an equivalence ratio of methane-air mixture, initial pressure and a width of the channel were varied in order to investigate effects of these parameters on characteristics of the flame propagation. As a result, the behavior of the flame entering into the narrow channel was classified into two phenomena, i.e. (i) the flame was quenched inside the narrow channel and combustion wave was not propagated into the downstream chamber, which results in just an emission of burned gaseous jet to the downstream chamber, (ii) the flame was propagated through the channel without quenching, which produced a high-pressure at both chambers.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.72.2018, ISSN：0387-5016, CiNii Articles ID：110004763450, CiNii Books ID：AN00187441
スリットに入射したデトネーション波の再開始過程<研究成果報告>
小原哲郎; 大八木重治
埼玉大学紀要, 工学部, 第1部論文集, 巻：39, 開始ページ：119, 終了ページ：126, 2006年
デトネーション駆動型衝撃風洞を用いたスクラムジェット燃焼器モデル内の燃焼過程(熱工学,内燃機関,動力など)
小原哲郎; 伊藤豪明; 大八木重治; 金泰煥; 坪井伸幸
日本機械学會論文集. B編, 巻：72, 号：718, 開始ページ：1596, 終了ページ：1604, 2006年
Experiments were conducted in order to investigate mixing and combustion processes in a model SCRAM (Supersonic Combustion RAM) jet combustor equipped with a backward-facing step. A detonation-driven shock tunnel was used to generate high-enthalpy flow of Mach number three. Firstly, an influence of installing a sidewall on the combustor model was investigated. Secondly, flow-fields around the step were visualized using high-speed video camera with an aid of schlieren technique. A hydrogen fuel was injected perpendicular to the supersonic flow behind the backward-facing step and a height of the step and an injection distance were varied in order to investigate the effects of these parameters on a characteristic of the combustion. As a result, the injected hydrogen was ignited behind the step and increasing the height of step became effective to the ignition and flame holding behaviors. Furthermore, a non-dimensional injection distance with respect to height of the step was considered to be an important parameter to influence an ignition and combustion processes in the model SCRAM jet combustor.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.72.1596, ISSN：0387-5016, CiNii Articles ID：110004758304, CiNii Books ID：AN00187441
狭い溝中を通過するデトネーション波の挙動に関する研究(熱工学,内燃機関,動力など)
小原哲郎; SENTANUHADY Jayan; 塚田豊; 大八木重治
日本機械学會論文集. B編, 巻：72, 号：718, 開始ページ：1605, 終了ページ：1612, 2006年
A detonation wave produced in a combustible gaseous mixture might cause serious damages by interacting with an artificial structure or human bodies because of an extremely high-pressure and high-temperature behind this wave. Therefore, the detonation wave produced in the gaseous mixture and propagated into a circumstance by accident should be attenuated or quenched within a short distance from its origin. Experiments were conducted in order to investigate behaviors of the detonation wave passing through narrow grooves, since the detonation wave was accompained with a cellular structure and no detonation wave could be propagated. In this study, the detonation wave produced in a gaseous mixture of hydrogen and oxygen was propagated through a grooved block and behaviors of the detonation wave were experimentally investigated by using techniques of pressure measurement and soot track record. As a result, the behavior of detonation wave propagating through the grooved block was classified into two categories, i. e. (i) the detonation wave was quenched, (ii) the detonation wave was once quenched behind the block but re-initiated again by focusing mechanisms of a reflected shock wave on a central axis.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.72.1605, ISSN：0387-5016, CiNii Articles ID：110004758305, CiNii Books ID：AN00187441
Laser Ablation with Water Micro-Drop for Dicing of Silicon Wafer
Journal of Laser Applications, 巻：18, 号：2, 開始ページ：127, 終了ページ：130, 2006年
スリット板背後におけるデトネーション波の再開始過程 (供試気体初期圧力の影響)
小原哲郎; Jayan Sentanuhady; 塚田豊; 大八木重治
日本機械学會論文集. B編, 巻：72, 号：724, 開始ページ：3158, 終了ページ：3165, 2006年
Experiments were conducted in order to investigate behaviors of a detonation wave propagating into two pieces of slit, since the detonation wave might be quenched behind a slit-plate by expansion waves generated at a corner of the plate and this technique might be applicable to a detonation arrestor. The detonation wave produced in a stoichiometric mixture of hydrogen and oxygen was propagated through the slits and behaviors of the detonation wave were experimentally investigated by using a technique of pressure measurement, soot track record and high-speed schlieren photography. As a result, when the detonation wave propagated through the slits, it was quenched and a schock wave was decoupled with a reaction front. Two shock waves diffracted from the slits interacted each other at centre of the tube, then this shock wave interaction induced a hot-spot enough to cause local explosions behind the slit-plate. Since the shock wave was reflected from the wall and interacted at centre of the tube, the detonation wave was re-initiated behind the slits.
一般社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.72.3158, ISSN：0387-5016, CiNii Articles ID：110006153443, CiNii Books ID：AN00187441
パルスデトネーションエンジンの安定作動に関するパージ空気の噴射量および分布の影響 桜井毅司; 大古壮了; 柚木聡; 吉橋照夫; 小原哲郎; 大八木重治
日本航空宇宙学会論文集. B編,
巻：54,
号：628,
開始ページ：204,
終了ページ：209, 2006年
For the development of Pulse Detonation Engine (PDE), effects of injected volume and distribution of purge-air gas on multiple-cycle operations of PDE were investigated. In order to improve the uniformity of a mixture, the experimental PDE had four sets of fuel and oxidizer injector in the opposite side at same axial location. In addition, an injector for the air purging was added on the thrust wall so that the direction of purging flow was discussed. In single cycle experiments, the air purging did not affect the pressure and propagation velocity of detonation wave, hence it is only effective for exhausting the burned gas. The amount of injected purging gas was varied in multiple-cycle experiments to find the optimum amount of purging for stable detonations. The results showed that the amount of air purging increased as the cycle frequency increased and the axial injection rather than the radial was effective to exhaust the burned gas.
一般社団法人 日本航空宇宙学会, 日本語
DOI：https://doi.org/10.2322/jjsass.54.204DOI ID：10.2322/jjsass.54.204,
ISSN：1344-6460,
CiNii Articles ID：10018055331,
CiNii Books ID：AA11307372 デトネーションアレスター技術の確立とメカニズムの解明
小原哲郎
総合研究機構研究プロジェクト研究成果報告書, 号：4(17年度), 2006年
狭い間隙に進入する火炎の挙動に関する実験的研究
小原 哲郎; 大八木 重治; 仁科 祐介; 成澤 伸之
日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B, 巻：72, 号：720, 開始ページ：2018, 終了ページ：2025, 2006年
A behavior of a flame propagating through a narrow channel is of importance, since this phenomenon is concerned with a quenching of the flame when heat losses by convective heat transfer or radiative one to a wall of channel are dominant and temperature behind the flame is not enough to increase that of unburned gases. Since, this phenomenon is also related to a safety-engineering problem where combustible gaseous mixture is handled, a device applying a narrow channel in a pipe might be one of useful technique to prevent the flame from propagating. Experiments were conducted to investigate a behavior of the flame propagating through a narrow channel, which connects two rectangular combustion chambers. The behavior of the flame was visualized using schlieren optical technique with an aid of high-speed video camera. In this study, an equivalence ratio of methane-air mixture, initial pressure and a width of the channel were varied in order to investigate effects of these parameters on characteristics of the flame propagation. As a result, the behavior of the flame entering into the narrow channel was classified into two phenomena, i.e. (i) the flame was quenched inside the narrow channel and combustion wave was not propagated into the downstream chamber, which results in just an emission of burned gaseous jet to the downstream chamber, (ii) the flame was propagated through the channel without quenching, which produced a high-pressure at both chambers.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.72.2018, ISSN：0387-5016, CiNii Articles ID：110004763450, CiNii Books ID：AN00187441
スリットに入射したデトネーション波の再開始過程<研究成果報告>小原 哲郎; 大八木 重治
埼玉大学紀要. 工学部 第1編 第1部 論文集,
巻：39,
開始ページ：119,
終了ページ：126, 2006年
Experiments were conducted in order to investigate behaviors of a detonation wave propagating into two pieces of slit, since the detonation wave might be quenched behind a slit-plate by expansion waves generated at a corner of the plate and this technique might be applicable to a detonation arrestor. The detonation wave produced in a stoichiometric mixture of hydrogen and oxygen was propagated through the slits and behaviors of the detonation wave were experimentally investigated by using a technique of pressure measurement, soot track record and high-speed schlieren photography. As a result, when the detonation wave propagated through the slits, it was quenched and a shock wave was decoupled with a reaction front. Two shock waves diffracted from the slits interacted each other at centre of the tube, then this shock wave interaction induced a hot-spot enough to cause local explosions behind the slit-plate. Since the shock wave was reflected from the wall and interacted at centre of the tube, the detonation wave was re-initiated behind the slits.
埼玉大学工学部, 日本語
ISSN：1880-4446,
CiNii Articles ID：120001370439 デトネーション駆動型衝撃風洞を用いたスクラムジェット燃焼器モデル内の燃焼過程
小原 哲郎; 伊藤 豪明; 金 泰煥; 大八木 重治; 坪井 伸幸
日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B, 巻：72, 号：718, 開始ページ：1596, 終了ページ：1604, 2006年
Experiments were conducted in order to investigate mixing and combustion processes in a model SCRAM (Supersonic Combustion RAM) jet combustor equipped with a backward-facing step. A detonation-driven shock tunnel was used to generate high-enthalpy flow of Mach number three. Firstly, an influence of installing a sidewall on the combustor model was investigated. Secondly, flow-fields around the step were visualized using high-speed video camera with an aid of schlieren technique. A hydrogen fuel was injected perpendicular to the supersonic flow behind the backward-facing step and a height of the step and an injection distance were varied in order to investigate the effects of these parameters on a characteristic of the combustion. As a result, the injected hydrogen was ignited behind the step and increasing the height of step became effective to the ignition and flame holding behaviors. Furthermore, a non-dimensional injection distance with respect to height of the step was considered to be an important parameter to influence an ignition and combustion processes in the model SCRAM jet combustor.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.72.1596, ISSN：0387-5016, CiNii Articles ID：110004758304, CiNii Books ID：AN00187441
狭い溝中を通過するデトネーション波の挙動に関する研究
小原 哲郎; Sentanuhady Jayan; 塚田 豊; 大八木 重治
日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B, 巻：72, 号：718, 開始ページ：1605, 終了ページ：1612, 2006年
A detonation wave produced in a combustible gaseous mixture might cause serious damages by interacting with an artificial structure or human bodies because of an extremely high-pressure and high-temperature behind this wave. Therefore, the detonation wave produced in the gaseous mixture and propagated into a circumstance by accident should be attenuated or quenched within a short distance from its origin. Experiments were conducted in order to investigate behaviors of the detonation wave passing through narrow grooves, since the detonation wave was accompained with a cellular structure and no detonation wave could be propagated. In this study, the detonation wave produced in a gaseous mixture of hydrogen and oxygen was propagated through a grooved block and behaviors of the detonation wave were experimentally investigated by using techniques of pressure measurement and soot track record. As a result, the behavior of detonation wave propagating through the grooved block was classified into two categories, i. e. (i) the detonation wave was quenched, (ii) the detonation wave was once quenched behind the block but re-initiated again by focusing mechanisms of a reflected shock wave on a central axis.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.72.1605, ISSN：0387-5016, CiNii Articles ID：110004758305, CiNii Books ID：AN00187441
Laser Ablation with Water Micro-Drop for Dicing of Silicon Wafer
巻：18, 号：2, 開始ページ：127, 終了ページ：130, 2006年
スリット板背後におけるデトネーション波の再開始過程 : 供試気体初期圧力の影響
小原 哲郎; Sentanuhady Jayan; 塚田 豊; 大八木 重治
日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B, 巻：72, 号：724, 開始ページ：3158, 終了ページ：3165, 2006年
Experiments were conducted in order to investigate behaviors of a detonation wave propagating into two pieces of slit, since the detonation wave might be quenched behind a slit-plate by expansion waves generated at a corner of the plate and this technique might be applicable to a detonation arrestor. The detonation wave produced in a stoichiometric mixture of hydrogen and oxygen was propagated through the slits and behaviors of the detonation wave were experimentally investigated by using a technique of pressure measurement, soot track record and high-speed schlieren photography. As a result, when the detonation wave propagated through the slits, it was quenched and a schock wave was decoupled with a reaction front. Two shock waves diffracted from the slits interacted each other at centre of the tube, then this shock wave interaction induced a hot-spot enough to cause local explosions behind the slit-plate. Since the shock wave was reflected from the wall and interacted at centre of the tube, the detonation wave was re-initiated behind the slits.
一般社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.72.3158, ISSN：0387-5016, CiNii Articles ID：110006153443, CiNii Books ID：AN00187441
パルスデトネーションエンジンの安定作動に関するパージ空気の噴射量および分布の影響 桜井 毅司; 大古 壮了; 柚木 聡; 吉橋 照夫; 小原 哲郎; 大八木 重治
日本航空宇宙学会論文集 = Journal of the Japan Society for Aeronautical and Space Sciences,
巻：54,
号：628,
開始ページ：204,
終了ページ：209, 2006年
For the development of Pulse Detonation Engine (PDE), effects of injected volume and distribution of purge-air gas on multiple-cycle operations of PDE were investigated. In order to improve the uniformity of a mixture, the experimental PDE had four sets of fuel and oxidizer injector in the opposite side at same axial location. In addition, an injector for the air purging was added on the thrust wall so that the direction of purging flow was discussed. In single cycle experiments, the air purging did not affect the pressure and propagation velocity of detonation wave, hence it is only effective for exhausting the burned gas. The amount of injected purging gas was varied in multiple-cycle experiments to find the optimum amount of purging for stable detonations. The results showed that the amount of air purging increased as the cycle frequency increased and the axial injection rather than the radial was effective to exhaust the burned gas.
一般社団法人 日本航空宇宙学会, 日本語
DOI：https://doi.org/10.2322/jjsass.54.204DOI ID：10.2322/jjsass.54.204,
ISSN：1344-6460,
CiNii Articles ID：10018055331,
CiNii Books ID：AA11307372 デトネーションアレスター技術の確立とメカニズムの解明
小原哲郎
号：4(17年度), 2006年
Investigation of the purge process on the multi-cycle operations of a pulse detonation engine T Sakurai; A Ooko; T Yoshihashi; T Obara; S Ohyagi
巻：48,
号：160,
開始ページ：78,
終了ページ：85, 2005年08月
The pulse detonation engine (PDE) is a propulsion system that generates thrust by repetitive detonation. Performance of the PDE, such as specific impulse, has gained much attention, However, the details of operational conditions related to performance have not been clarified. In this Study, to investigate these issues. The hydrogen-air PDE was constructed and the effect of the purge process on multi-cycle operations was studied. The exhaust of the burned gas front the PDE was made by rarefaction waves so that it is expected not to create internal disturbance, such as, spiral in the tube so that the burned gas can be exhausted smoothly. A purge process using air was applied to assist the exhaust process in order to prevent failures in multi-cycle operations. The effects of the purge-volume fraction were investigated. As a result when a purge-air gas filled the region including the spark plug detonations occurred in a table manner. Using these conditions. multi-cycle experiments ranging from 10 to 50 Hz were conducted and profiles of wall thrust-wall pressure are discussed in detail.
英語
DOI：https://doi.org/10.2322/tjsass.48.78DOI ID：10.2322/tjsass.48.78,
ISSN：0549-3811,
CiNii Articles ID：10016766214,
Web of Science ID：WOS:000231206400004 研究プロジェクト「マイクロ／ナノスケール計測制御テクノセンタ ー」活動報告<研究成果報告>
水野毅; 川橋正昭; 大八木重治; 加藤寛; 佐藤勇一; 堀尾健一郎; 豊岡了; 荒居善雄; 綿貫啓一; 池野順一; 小原哲郎; 高崎正也
埼玉大学紀要, 工学部, 第1部論文集, 巻：1, 号：38, 開始ページ：114, 終了ページ：118, 2005年
レーザダイシング技術の開発
レーザ加工学会誌, 巻：12, 号：6, 2005年
ロータリーバルブを装着したPDE のデトネーション作動に関する研究
柚木聡; 桜井毅司; 笹森崇志; 小原哲郎; 大八木重治; 村山元英
埼玉大学地域共同研究センター紀要, 巻：6, 号：6, 開始ページ：58, 終了ページ：62, 2005年
A PDE equipped with the rotary-valve was constructed. Fuel, which is hydrogen, was injected by the solenoid valve. The porous plates was used to promote the mixing of fuel-air mixture. In this paper, multi-cycle operations for 20Hz, 4.5 second were conducted. It was investigated that what kind of porous shape and the fuel injection position were effective to the mixing and subsequent detonation process. As a result, the "IP2", which was downward injection to the air, was the best for the fuel injection position. The porous plate "P3" that has large open ratio and small aperture size was effective to the mixing and detonation. Detonations were not obtained at all cycles because the mixture could not be filled to the combustion tube uniformly.
埼玉大学総合研究機構地域共同研究センター産学連携推進部門, 日本語
ISSN：1347-4758, CiNii Articles ID：120001371337, CiNii Books ID：AA11808968
スクラムジェットエンジンの開発を目指した基礎研究
小原哲郎
総合研究機構研究プロジェクト研究成果報告書, 巻：16年度, 2005年
研究プロジェクト「マイクロ／ナノスケール計測制御テクノセンタ ー」活動報告<研究成果報告>
水野毅; 川橋正昭; 大八木重治; 加藤寛; 佐藤勇一; 堀尾健一郎; 豊岡了; 荒居善雄; 綿貫啓一; 池野順一; 小原哲郎; 高崎正也
巻：1, 号：38, 開始ページ：114, 終了ページ：118, 2005年
レーザダイシング技術の開発
巻：12, 号：6, 2005年
ロータリーバルブを装着したPDEのデトネーション作動に関する研究
柚木 聡; 桜井 毅司; 笹森 崇志; 小原 哲郎; 大八木 重治; 村山 元英
埼玉大学地域共同研究センター紀要, 巻：6, 号：6, 開始ページ：58, 終了ページ：62, 2005年
A PDE equipped with the rotary-valve was constructed. Fuel, which is hydrogen, was injected by the solenoid valve. The porous plates was used to promote the mixing of fuel-air mixture. In this paper, multi-cycle operations for 20Hz, 4.5 second were conducted. It was investigated that what kind of porous shape and the fuel injection position were effective to the mixing and subsequent detonation process. As a result, the "IP2", which was downward injection to the air, was the best for the fuel injection position. The porous plate "P3" that has large open ratio and small aperture size was effective to the mixing and detonation. Detonations were not obtained at all cycles because the mixture could not be filled to the combustion tube uniformly.
埼玉大学総合研究機構地域共同研究センター産学連携推進部門, 日本語
ISSN：1347-4758, CiNii Articles ID：120001371337, CiNii Books ID：AA11808968
スクラムジェットエンジンの開発を目指した基礎研究
小原哲郎
巻：16年度, 2005年
デトネーション波により駆動される衝撃波管の作動特性に関する実験的研究(熱工学,内燃機関,動力など) 金泰煥; 小原; 哲郎; 大八木重治; 吉川正人
日本機械学會論文集. B編,
巻：70,
号：691,
開始ページ：707,
終了ページ：714, 2004年
DOI：https://doi.org/10.1299/kikaib.70.707DOI ID：10.1299/kikaib.70.707,
ISSN：0387-5016,
CiNii Articles ID：110004999317 A Study for Development of Hydrogen-fueled Pulse Detonation Engines
Sakurai T; Minagawa T; Yoshihashi T; Obara T; Ohyagi S
Science and Technology of Energetic Materials, 巻：65, 号：4, 開始ページ：125, 終了ページ：133, 2004年
デトネーション駆動型衝撃風洞を用いた後ろ向きステップ周りの流れ場に関する実験的研究 金泰煥; 小原哲郎; 大八木重治; 吉川正人
日本航空宇宙学会論文集,
巻：52,
号：608,
開始ページ：385,
終了ページ：392, 2004年
DOI：https://doi.org/10.2322/jjsass.52.385DOI ID：10.2322/jjsass.52.385,
ISSN：1344-6460,
CiNii Articles ID：10013578099 デトネーション波により駆動される衝撃波管の作動特性に関する実験的研究(熱工学,内燃機関,動力など) 金泰煥; 小原; 哲郎; 大八木重治; 吉川正人
巻：70,
号：691,
開始ページ：707,
終了ページ：714, 2004年
DOI：https://doi.org/10.1299/kikaib.70.707DOI ID：10.1299/kikaib.70.707,
ISSN：0387-5016,
CiNii Articles ID：110004999317 A Study for Development of Hydrogen-fueled Pulse Detonation Engines
Sakurai T; Minagawa T; Yoshihashi T; Obara T; Ohyagi S
巻：65, 号：4, 開始ページ：125, 終了ページ：133, 2004年
デトネーション駆動型衝撃風洞を用いた後ろ向きステップ周りの流れ場に関する実験的研究 金泰煥; 小原哲郎; 大八木重治; 吉川正人
巻：52,
号：608,
開始ページ：385,
終了ページ：392, 2004年
DOI：https://doi.org/10.2322/jjsass.52.385DOI ID：10.2322/jjsass.52.385,
ISSN：1344-6460,
CiNii Articles ID：10013578099 Diffraction and re-initiation of detonations behind a backward-facing step S Ohyagi; T Obara; S Hoshi; P Cai; T Yoshihashi
巻：12,
号：3,
開始ページ：221,
終了ページ：226, 2002年11月
Diffraction phenomena of gaseous detonation waves behind a backward-facing step in a tube are observed by using high-speed schlieren photography and soot-track records as well as by pressure measurements on the sidewall. Mixtures are stoichiometric oxyhydrogen and those diluted by argon at sub-atmospheric pressures. Three types of phenomena are observed, that is, continuous propagation of detonation, re-initiation after a temporal extinction of detonation and complete extinction of detonation. The continuous propagation means that the diffracted wave does not affect the main propagation although reflected shock waves from the bottom surface of the tube may affect it. The re-initiation occurs at a wall surface of the tube behind a reflected shock wave after the main detonation wave has been extinguished. Positions and conditions of the re-initiation are discussed. The complete extinction is defined as disappearance of detonation cells behind the step within a certain length of the tube. Cases exist where an ignition occurs after several reflections off the bottom and top surface of the tube.
英語
DOI：https://doi.org/10.1007/s00193-002-0156-zDOI ID：10.1007/s00193-002-0156-z,
ISSN：0938-1287,
Web of Science ID：WOS:000179514200006 Study on performance of detonation-driven shock tube A Yamanaka; Y Ariga; T Obara; P Cai; S Ohyagi
巻：45,
号：2,
開始ページ：425,
終了ページ：431, 2002年05月
A detonation-driven shock tube firstly designed by H.R. Yu is considered to be a useful apparatus for producing high-enthalpy flow. In this apparatus, a strong shock wave is generated by detonating an oxygen-hydrogen mixture (oxy-hydrogen) and the driver gas temperature and pressure are extremely high compared with those of a conventional shock tube. However, the structure of the detonation wave is not uniform, e.g., the detonation wave has three-dimensional cellular structures and multiple transverse waves. Furthermore, the detonation wave is followed by a Taylor expansion fan and the performance of detonation-driven shock tube is not well understood. In this preliminary study, a detonation-driven shock tube is constructed and its performance is experimentally investigated by measuring pressure histories and the profile of the ionization current behind the detonation wave. As a result, (i) the pressure history of the detonation wave is clarified and shows reasonable agreement with the result obtained by the KASIMIR shock tube simulation code. (ii) The propagation velocity of the detonation wave coincides well with the theoretical prediction assuming a Chapman-Jouguet detonation wave. (iii) The equivalence ratio of the oxy-hydrogen mixture to produce the highest Mach number of the shock wave is evaluated to be phisimilar or equal to1.7.
英語
DOI：https://doi.org/10.1299/jsmeb.45.425DOI ID：10.1299/jsmeb.45.425,
ISSN：1340-8054,
Web of Science ID：WOS:000176689400025 Propagation of pressure waves initiated by flame and detonation in a tube S Ohyagi; E Nohira; T Obara; P Cai; T Yoshihashi
巻：45,
号：1,
開始ページ：192,
終了ページ：200, 2002年02月
Pressure waves produced by explosions of combustible mixtures formed by the accidental spillage of fuel gases have attracted considerable attention from the safety point of view. In order to assess damage caused by such explosion hazards, real-scale experiments are necessary. However, it is often difficult to perform such experiments because of space limitations and experimental safety. Small-scale experiments are preferred if an appropriate scaling law can be verified. The objectives of this study are to elucidate the decay processes of planar blast waves initiated by deflagration and detonation waves in a tube and to assess the applicability of the energy-based scaling law to these phenomena.
英語
DOI：https://doi.org/10.1299/jsmeb.45.192DOI ID：10.1299/jsmeb.45.192,
ISSN：1340-8054,
CiNii Articles ID：110003479029,
Web of Science ID：WOS:000174734800031 開放端から放出された衝撃波に関する実験と数値シミュレーション(流体工学,流体機械) 小原哲郎; 大八木重治; 加藤肇; 有賀洋介
日本機械学會論文集. B編,
巻：68,
号：668,
開始ページ：1036,
終了ページ：1043, 2002年
DOI：https://doi.org/10.1299/kikaib.68.1036DOI ID：10.1299/kikaib.68.1036,
ISSN：0387-5016,
CiNii Articles ID：110002387082 開放端から放出された衝撃波に関する実験と数値シミュレーション(流体工学,流体機械) 小原哲郎; 大八木重治; 加藤肇; 有賀洋介
巻：68,
号：668,
開始ページ：1036,
終了ページ：1043, 2002年
DOI：https://doi.org/10.1299/kikaib.68.1036DOI ID：10.1299/kikaib.68.1036,
ISSN：0387-5016,
CiNii Articles ID：110002387082 回折する衝撃波の挙動に関する研究 : 第2報、溝付き開放端による衝撃波の減衰過程 : 流体工学,流体機械 小原哲郎; 大八木重治; 高藤亮一; 蔡品
日本機械学會論文集. B編,
巻：67,
号：659,
開始ページ：1680,
終了ページ：1686, 2001年
DOI：https://doi.org/10.1299/kikaib.67.1680DOI ID：10.1299/kikaib.67.1680,
ISSN：0387-5016,
CiNii Articles ID：110002397664 回折する衝撃波の挙動に関する研究 : 第2報、溝付き開放端による衝撃波の減衰過程 : 流体工学,流体機械 小原哲郎; 大八木重治; 高藤亮一; 蔡品
巻：67,
号：659,
開始ページ：1680,
終了ページ：1686, 2001年
DOI：https://doi.org/10.1299/kikaib.67.1680DOI ID：10.1299/kikaib.67.1680,
ISSN：0387-5016,
CiNii Articles ID：110002397664 A numerical simulation of reflection processes of a detonation wave on a wedge
S Ohyagi; T Obara; F Nakata; S Hoshi
巻：10, 号：3, 開始ページ：185, 終了ページ：190, 2000年07月
A two dimensional numerical simulation has been performed to study reflection processes of detonation waves on a wedge. The numerical scheme adopted is the Aux corrected transport scheme and a two-step chemical reaction is assumed for a stoichiometric oxyhydrogen mixture diluted with argon. Transverse wave structures of the detonation are produced by artificial disturbances situated in front of a one-dimensional Chapman-Jouguet detonation wave. Numerical grids are generated by solving a Laplace equation. Results show that in the case where Mach reflection occurs, the cells in the Mach stem are smaller than those in the incident wave and are distorted in shape. There is also an initiating stage during which the cells in the Mach stem are created. The critical angle beyond which Mach reflection cannot occur is discussed.
英語
ISSN：0938-1287, Web of Science ID：WOS:000088471900005
デトネーション駆動形衝撃波管の作動特性 山中昭央; 有賀洋介; 小原哲郎; 蔡品; 大八木重治
日本機械学會論文集. B編,
巻：66,
号：651,
開始ページ：2992,
終了ページ：2998, 2000年
DOI：https://doi.org/10.1299/kikaib.66.651_2992DOI ID：10.1299/kikaib.66.651_2992,
ISSN：0387-5016,
CiNii Articles ID：110002392687 気体デトネーションの構造とその反射・回折現象
大八木 重治; 星 真太郎; 小原 哲郎
燃焼の科学と技術, 巻：7, 号：4, 開始ページ：249, 終了ページ：263, 2000年
サイエンス・コミュニケーションズ・インターナショナル, 日本語
ISSN：0918-5712, CiNii Articles ID：40004994521, CiNii Books ID：AN10436291
デトネーション駆動形衝撃波管の作動特性 山中昭央; 有賀洋介; 小原哲郎; 蔡品; 大八木重治
巻：66,
号：651,
開始ページ：2992,
終了ページ：2998, 2000年
DOI：https://doi.org/10.1299/kikaib.66.651_2992DOI ID：10.1299/kikaib.66.651_2992,
ISSN：0387-5016,
CiNii Articles ID：110002392687 気体デトネーションの構造とその反射・回折現象 (火災・爆発特集)
大八木 重治; 星 真太郎; 小原 哲郎
燃焼の科学と技術, 巻：7, 号：4, 開始ページ：249, 終了ページ：263, 2000年
サイエンス・コミュニケーションズ・インターナショナル, 日本語
ISSN：0918-5712, CiNii Articles ID：40004994521, CiNii Books ID：AN10436291
回折する衝撃波の挙動に関する研究 : 第1報, 衝撃波の回折と反射過程 高藤亮一; 山中昭央; 小原哲郎; 蔡品; 大八木重治
日本機械学會論文集. B編,
巻：65,
号：639,
開始ページ：3602,
終了ページ：3607, 1999年
DOI：https://doi.org/10.1299/kikaib.65.3602DOI ID：10.1299/kikaib.65.3602,
ISSN：0387-5016,
CiNii Articles ID：110002395677 後向きステップ後方に安定化される平面的拡散火炎に関する数値解析
王 暁; 小原 哲郎; 大八木 重治
日本機械学會論文集. B編, 巻：65, 号：632, 開始ページ：1446, 終了ページ：1451, 1999年
A numerical study on a planar diffusion flame stabilized behind a backward-facing step is performed. Computational model is set to simulate our experimental study where a fuel gas is supplied from a porous plate behind the backward-facing step. A flame sheet model is used because the simulation is focused on the stabilized flame. The computational scheme is the SIMPLE with the QUICK for convection terms. Although the model is restricted to two-dimensional, the results show that the flame deforms due to the Kelvin-Helmholtz instability arising from the density change due to combustion. Comparison with the experiment is succesfully performed by the schlieren photography and the temperature variation.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.65.1446, ISSN：0387-5016, CiNii Articles ID：110002395377, CiNii Books ID：AN00187441
回折する衝撃波の挙動に関する研究 : 第1報, 衝撃波の回折と反射過程 高藤亮一; 山中昭央; 小原哲郎; 蔡品; 大八木重治
巻：65,
号：639,
開始ページ：3602,
終了ページ：3607, 1999年
DOI：https://doi.org/10.1299/kikaib.65.3602DOI ID：10.1299/kikaib.65.3602,
ISSN：0387-5016,
CiNii Articles ID：110002395677 後向きステップ後方に安定化される平面的拡散火炎に関する数値解析
Rohmat Tri Agung; 王 暁; 小原 哲郎; 大八木 重治
日本機械学会論文集. B編, 巻：65, 号：632, 開始ページ：1446, 終了ページ：1451, 1999年
A numerical study on a planar diffusion flame stabilized behind a backward-facing step is performed. Computational model is set to simulate our experimental study where a fuel gas is supplied from a porous plate behind the backward-facing step. A flame sheet model is used because the simulation is focused on the stabilized flame. The computational scheme is the SIMPLE with the QUICK for convection terms. Although the model is restricted to two-dimensional, the results show that the flame deforms due to the Kelvin-Helmholtz instability arising from the density change due to combustion. Comparison with the experiment is succesfully performed by the schlieren photography and the temperature variation.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.65.1446, ISSN：0387-5016, CiNii Articles ID：110002395377, CiNii Books ID：AN00187441
Diffusion flame stabilized on a porous plate in a parallel airstream TA Rohmat; H Katoh; T Obara; T Yoshihashi; S Ohyagi
巻：36,
号：11,
開始ページ：1945,
終了ページ：1952, 1998年11月
Effects of an obstacle on the structure and stability of a laminar diffusion flame established on a porous plate in a parallel airstream have been investigated experimentally. The obstacle, a backward-facing step or a rectangular cylinder, is located upstream of the porous plate through which gaseous methane is injected uniformly. Structures of the flame are elucidated by the direct and schlieren photography. Flame shapes are described and stability diagrams are plotted for the freestream velocity and the fuel injection velocity, which are discussed with flow structures.
英語
DOI：https://doi.org/10.2514/2.300DOI ID：10.2514/2.300,
ISSN：0001-1452,
Web of Science ID：WOS:000077014000001 フィルムデトネーション波開始過程の可視化(流体工学, 流体機械)
渡辺真次; 小原哲郎; 吉橋照夫; 大八木重治
日本機械学會論文集. B編, 巻：63, 号：612, 開始ページ：2700, 終了ページ：2706, 1997年
The detonation wave caused by the combustion of a liquid fuel film coated on an inner tube wall has recently attracted considerable attention because of its possible role in explosion hazards in compressed oxygen pipelines. This type of detonation is known as "film detonation" and is classified as a heterogeneous detonation. The structure of a heterogeneous detonation wave is very complex because physical processes such as momentum, heat and mass exchanges between liquid film and the gas phase are coupled with a chemical reaction. Experiments are conducted to investigate the initiation process of film detonation using high-speed schlieren photography and direct photography. It is clearly observed that a secondary shock wave caused by the combustion of liquid fuel film plays a significant role in the transition of film detonation wave.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.63.2700, ISSN：0387-5016, CiNii Articles ID：110002396555, CiNii Books ID：AN00187441
High-speed Photography and Stress Gauge Studies of Jet Impact upon Surfaces BOURNE N K; OBARA T; FIELD J E
Philosophical Transaction Royal Society of London,
巻：355,
号：1724,
開始ページ：607,
終了ページ：623, 1997年
DOI：https://doi.org/10.1098/rsta.1997.0028DOI ID：10.1098/rsta.1997.0028,
ISSN：1364-503X,
CiNii Articles ID：80009525259 フィルムデトネーション波開始過程の可視化
渡辺 真次; 小原 哲郎; 吉橋 照夫; 大八木 重治
日本機械学会論文集. B編, 巻：63, 号：612, 開始ページ：2700, 終了ページ：2706, 1997年
The detonation wave caused by the combustion of a liquid fuel film coated on an inner tube wall has recently attracted considerable attention because of its possible role in explosion hazards in compressed oxygen pipelines. This type of detonation is known as "film detonation" and is classified as a heterogeneous detonation. The structure of a heterogeneous detonation wave is very complex because physical processes such as momentum, heat and mass exchanges between liquid film and the gas phase are coupled with a chemical reaction. Experiments are conducted to investigate the initiation process of film detonation using high-speed schlieren photography and direct photography. It is clearly observed that a secondary shock wave caused by the combustion of liquid fuel film plays a significant role in the transition of film detonation wave.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.63.2700, ISSN：0387-5016, CiNii Articles ID：110002396555, CiNii Books ID：AN00187441
High-speed Photography and Stress Gauge Studies of Jet Impact upon Surfaces 巻：355,
号：1724,
開始ページ：607,
終了ページ：623, 1997年
DOI：https://doi.org/10.1098/rsta.1997.0028DOI ID：10.1098/rsta.1997.0028,
ISSN：1364-503X,
CiNii Articles ID：80009525259 A high-speed photographic study of the transition from deflagration to detonation wave T Obara; S Yajima; T Yoshihashi; S Ohyagi
巻：6,
号：4,
開始ページ：205,
終了ページ：210, 1996年10月
Experiments were conducted to investigate the DDT process of the oxyhydrogen gas in the rectangular detonation tube of 3 m long. The repeated obstacle was installed near the ignition plug and the effects of the obstacle on the DDT process were investigated. The behaviour of the combustion and detonation wave were visualized utilizing Imacon high-speed camera with the aid of Schlieren optics.
As a result, DDT process was visualized, i.e. (i) multiple shock waves were induced by the expanding combustion wave, because the combustion flame played a role as a piston and compressed the unburned gases. (ii) The acceleration of the combustion wave was occurred and the distance between the shock wave and the combustion flame became shorter. (iii) Eventually, the local explosion was occurred and cause overdriven detonation wave to propagate at the velocity of about 3 kms(-1).
英語
DOI：https://doi.org/10.1007/s001930050038DOI ID：10.1007/s001930050038,
ISSN：0938-1287,
eISSN：1432-2153,
CiNii Articles ID：10012694180,
Web of Science ID：WOS:A1996VN82400003 The Impact and Penetration of a Water Surface by a Liquid Jet BOURNE N K; OBARA T; FIELD J E
Proc. Royal Society of London,
巻：452,
号：1949,
開始ページ：1497,
終了ページ：1502, 1996年
DOI：https://doi.org/10.1098/rspa.1996.0077DOI ID：10.1098/rspa.1996.0077,
ISSN：1364-5021,
CiNii Articles ID：80009046297 The Impact and Penetration of a Water Surface by a Liquid Jet 巻：452,
号：1949,
開始ページ：1497,
終了ページ：1502, 1996年
DOI：https://doi.org/10.1098/rspa.1996.0077DOI ID：10.1098/rspa.1996.0077,
ISSN：1364-5021,
CiNii Articles ID：80009046297 LIQUID-JET IMPACT ON LIQUID AND SOLID-SURFACES T OBARA; NK BOURNE; JE FIELD
巻：186,
号：2,
開始ページ：388,
終了ページ：394, 1995年08月
Experiments were conducted to investigate the mechanisms of the liquid-jet impact on liquid and solid surfaces associated with cavitation damage and rain erosion. In this work, a liquid jet of 3 mm diameter, generated using a single impact jet apparatus, was impacted at ca. 600 m s(-1) on the surface of water and polymethyl-methacrylate (PMMA) placed 15 mm below the nozzle exit. The various phenomena which occurred were photographed using an image-converter high-speed camera. These include (i) the shock wave generated at the moment of the liquid-jet impact on the surface, (ii) shock waves reflected at the liquid/air or solid/air interfaces, as release waves, (iii) the damage to the PMMA, (iv) the overlap of release waves on the central axis, causing central damage in PMMA and cavitation in liquids. The cavitation behaviour and the process of the damage is directly related to the behaviour of the compressive wave caused by the impact of the liquid jet.
英語
DOI：https://doi.org/10.1016/0043-1648(95)07187-3DOI ID：10.1016/0043-1648(95)07187-3,
ISSN：0043-1648,
Web of Science ID：WOS:A1995RW62000007 The Construction and Calibration of an Inexpensive PVDF Stress Gauge for Fast Pressure Measurements OBARA T; BOURNE N K; MEBAR Y
Meas. Sci. Technology,
巻：6,
号：4,
開始ページ：345,
終了ページ：348, 1995年
DOI：https://doi.org/10.1088/0957-0233/6/4/001DOI ID：10.1088/0957-0233/6/4/001,
ISSN：0957-0233,
CiNii Articles ID：80008225034 A Stress Gauge for Use in Electrically Noisy Environments BOURNE N K; MEBAR Y; OBARA T
Meas. Sci. Technology,
巻：6,
号：12,
開始ページ：1659,
終了ページ：1661, 1995年
DOI：https://doi.org/10.1088/0957-0233/6/12/002DOI ID：10.1088/0957-0233/6/12/002,
ISSN：0957-0233,
CiNii Articles ID：80008709769 The Construction and Calibration of an Inexpensive PVDF Stress Gauge for Fast Pressure Measurements 巻：6,
号：4,
開始ページ：345,
終了ページ：348, 1995年
DOI：https://doi.org/10.1088/0957-0233/6/4/001DOI ID：10.1088/0957-0233/6/4/001,
ISSN：0957-0233,
CiNii Articles ID：80008225034 A Stress Gauge for Use in Electrically Noisy Environments 巻：6,
号：12,
開始ページ：1659,
終了ページ：1661, 1995年
DOI：https://doi.org/10.1088/0957-0233/6/12/002DOI ID：10.1088/0957-0233/6/12/002,
ISSN：0957-0233,
CiNii Articles ID：80008709769 Cavitation phenomena in extracorporeal microexplosion lithotripsy Y. Tomita; T. Obara; K. Takayama; M. Kuwahara
巻：3,
号：3,
開始ページ：149,
終了ページ：157, 1994年09月
An experimental investigation was made of cavitation phenomena induced by underwater shock wave focusing applied to the extracorporeal microexplosion lithotripsy (microexplosion ESWL). Firstly an underwater microexplosion generated by detonation of a 10 mg silver azide pellet was studied and secondly underwater shock focusing and its induced cavitation phenomena were investgated. Underwater shock wave was focused by using a semi-ellipsoidal reflector in which a shock wave generated at the first focal point of the reflector was reflected and focused at the second focal point. It is found that an explosion product gas bubble did not produce any distinct rebound shocks. Meantime cavitation appeared after shock focusing at the second focal point where expansion waves originated at the exit of the reflector were simultaneously collected. A shock/bubble interaction is found to contribute not only to urinary tract stone disintegration but also tissue damage. The cavitation effect associated with the microexplosion ESWL was weaker in comparison with a spark discharge ESWL. The microexplosion ESWL is an effective method which can minimize the number of shock exposures hence decreasing tissue damage by conducting precise positioning of urinary tract stones. © 1994 Springer-Verlag.
英語
DOI：https://doi.org/10.1007/BF01414709DOI ID：10.1007/BF01414709,
ISSN：0938-1287,
SCOPUS ID：0000121423 デフラグレーション波からデトネーション波への遷移過程 : 障害物の影響
大八木重治; 小原哲郎; 吉橋照夫; 矢島智
日本機械学會論文集. B編, 巻：59, 号：567, 開始ページ：3552, 終了ページ：3556, 1993年
Transition processes from deflagration to detonation waves in stoichiometric oxyhydrogen mixtures diluted with nitrogen were observed using high-speed Schlieren photography as well as pressure and ionization current measurements. In this study, effects of obstacles on the transition processes were investigated. The obstacles were multigutter shaped and were installed near an ignition plug on an inner wall of a rectangular tube. Width and depth of the gutter were selected as parameters while composition of the mixture was fixed. It was revealed that there exist optimum values of these parameters for enhancing the transition to detonation.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.59.3552, ISSN：0387-5016, CiNii Articles ID：110002392297, CiNii Books ID：AN00187441
デフラグレ-ション波からデトネ-ション波への遷移過程--障害物の影響
大八木 重治; 矢島 智; 小原 哲郎; 吉橋 照夫
日本機械学会論文集 B編, 巻：59, 号：567, 開始ページ：3552, 終了ページ：3556, 1993年
Transition processes from deflagration to detonation waves in stoichiometric oxyhydrogen mixtures diluted with nitrogen were observed using high-speed Schlieren photography as well as pressure and ionization current measurements. In this study, effects of obstacles on the transition processes were investigated. The obstacles were multigutter shaped and were installed near an ignition plug on an inner wall of a rectangular tube. Width and depth of the gutter were selected as parameters while composition of the mixture was fixed. It was revealed that there exist optimum values of these parameters for enhancing the transition to detonation.
社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.59.3552, ISSN：0387-5016, CiNii Articles ID：110002392297, CiNii Books ID：AN00187441
閉じた回転楕円体容器内での水中衝撃波フォーカッシングによる超高圧生成についての研究
工業火薬, 巻：52, 号：4, 開始ページ：301, 終了ページ：306, 1991年
水中微小爆発による衝撃波フォーカッシング医療応用への基礎研究
高山 和喜; 小野寺 収; 小原 哲郎; 桑原 正明; 北山 修
日本機械学會論文集. B編, 巻：57, 号：539, 開始ページ：2285, 終了ページ：2292, 1991年
This is a preliminary report of an application of underwater shock wave focusing to the so-called extracorporeal shock wave lithotripsy, ESWL. Underwater spherical shock waves were initiated by microexplosions at one of two focus points of an ellipsoidal cavity. Consequently, the reflected shock waves were focused at the second focus point outside the ellipsoidal reflector, and high pressure was generated for a few microseconds. To the shock wave propagation, human tissue has a character very similar to that of water, and we can generate high pressure inside the human body by shock wave focusing sufficient to disintegrate human calculi. This paper reports an experimental and numerical approach of determining the most effective shape of ellipsoidal reflector for the lithotriptor and clarifying the mechanism of focused high-pressure generation by microexplosions. It was found that a half-ellipsoidal shape having a major and minor axis ratio of about 1.4〜1.5 was very suitable for the lithotriptor.
一般社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.57.2285, ISSN：0387-5016, CiNii Articles ID：110002389908, CiNii Books ID：AN00187441
閉じた回転楕円体容器内での水中衝撃波フォ-カッシングによる超高圧生成についての研究
亀島 望
工業火薬, 巻：52, 号：4, 開始ページ：301, 終了ページ：306, 1991年
工業火薬協会, 日本語
ISSN：0368-6450, CiNii Articles ID：40004627429, CiNii Books ID：AN1016662X
水中微小爆発による衝撃波フォ-カッシング医療応用への基礎研究
高山 和喜; 小野寺 収; 小原 哲郎; 桑原 正明; 北山 修
日本機械学会論文集 B編, 巻：57, 号：539, 開始ページ：2285, 終了ページ：2292, 1991年
This is a preliminary report of an application of underwater shock wave focusing to the so-called extracorporeal shock wave lithotripsy, ESWL. Underwater spherical shock waves were initiated by microexplosions at one of two focus points of an ellipsoidal cavity. Consequently, the reflected shock waves were focused at the second focus point outside the ellipsoidal reflector, and high pressure was generated for a few microseconds. To the shock wave propagation, human tissue has a character very similar to that of water, and we can generate high pressure inside the human body by shock wave focusing sufficient to disintegrate human calculi. This paper reports an experimental and numerical approach of determining the most effective shape of ellipsoidal reflector for the lithotriptor and clarifying the mechanism of focused high-pressure generation by microexplosions. It was found that a half-ellipsoidal shape having a major and minor axis ratio of about 1.4〜1.5 was very suitable for the lithotriptor.
一般社団法人日本機械学会, 日本語
DOI ID：10.1299/kikaib.57.2285, ISSN：0387-5016, CiNii Articles ID：110002389908, CiNii Books ID：AN00187441
水中衝撃波のフォーカッシンング現象と高圧発生のメカニズム 高山 和喜; 小原 哲郎; 斉藤 和男; 亀島 望
日本機械学會論文集. B編,
巻：56,
号：526,
開始ページ：1579,
終了ページ：1582, 1990年
Underwater spherical shock focusing can be obtained in a closed ellipsoidal-shaped cavity by the explosion of a small silver azide pellet. The present paper reports on an experimental and numerical study of the generation of high pressure and its mechanism. The shock focusing pressure was measured in a 500mmx700mm ellipsoidal cavity with a PVDF pressure transducer which has a wide frequency response. A high pressure of 3000bar was obtained for a 100mg silver azide pellet. The process of shock focusing was also studied numerically by the TVD finite difference scheme. A quantitative agreement was obtained between the experiment and the simulation. It was demonstrated that the underwater shock focusing is one of the most efficient methods to obtain a controlled high pressure in a small region.
The Japan Society of Mechanical Engineers, 日本語
DOI：https://doi.org/10.1299/kikaib.56.1579DOI ID：10.1299/kikaib.56.1579,
ISSN：0387-5016,
CiNii Articles ID：110002388991 弱い衝撃波と気泡の干渉に関する一実験 (単一および2個の気泡の崩壊時に発生する液体マイクロジェットの挙動) 小原 哲郎; 杉山 弘; 新井 隆景; 平岩 恒二
日本機械学會論文集. B編,
巻：56,
号：526,
開始ページ：1583,
終了ページ：1587, 1990年
This paper is concerned with the interaction between a weak-plane shock wave and bubbles. The behavior of a liquid microjet produced by the collapse of single and double bubbles was observed using a water shock tube, Ima-Con high speed camera and a PVDF pressure sensor with a high frequency response. The behavior of single collapsing bubble agrees qualitatively with previous experimental results, and it is shown that the present experimental method is effective in investigating the bubble collapse and generation of impulsive pressure. The speed of a microjet within the bubble is estimated to be about 100 m/s, or about ten times as much as that of a microjet penetrating the other side of the bubble surface. In the case of double collapsing bubbles the direction of microjet formation is different from the case of single bubble collapse.
The Japan Society of Mechanical Engineers, 日本語
DOI：https://doi.org/10.1299/kikaib.56.1583DOI ID：10.1299/kikaib.56.1583,
ISSN：0387-5016,
CiNii Articles ID：110002388993 水中衝撃波のフォーカッシング現象と高圧発生のメカニズム 高山 和喜; 小原 哲郎; 斉藤 和男; 亀島 望
日本機械学会論文集 B編,
巻：56,
号：526,
開始ページ：1579,
終了ページ：1582, 1990年
Underwater spherical shock focusing can be obtained in a closed ellipsoidal-shaped cavity by the explosion of a small silver azide pellet. The present paper reports on an experimental and numerical study of the generation of high pressure and its mechanism. The shock focusing pressure was measured in a 500mmx700mm ellipsoidal cavity with a PVDF pressure transducer which has a wide frequency response. A high pressure of 3000bar was obtained for a 100mg silver azide pellet. The process of shock focusing was also studied numerically by the TVD finite difference scheme. A quantitative agreement was obtained between the experiment and the simulation. It was demonstrated that the underwater shock focusing is one of the most efficient methods to obtain a controlled high pressure in a small region.
The Japan Society of Mechanical Engineers, 日本語
DOI：https://doi.org/10.1299/kikaib.56.1579DOI ID：10.1299/kikaib.56.1579,
ISSN：0387-5016,
CiNii Articles ID：110002388991 弱い衝撃波と気泡の干渉に関する一実験 単一および２個の気泡の崩壊時に発生する液体マイクロジェットの挙動 小原 哲郎; 杉山 弘; 新井 隆景; 平岩 恒二
日本機械学会論文集 B編,
巻：56,
号：526,
開始ページ：1583,
終了ページ：1587, 1990年
This paper is concerned with the interaction between a weak-plane shock wave and bubbles. The behavior of a liquid microjet produced by the collapse of single and double bubbles was observed using a water shock tube, Ima-Con high speed camera and a PVDF pressure sensor with a high frequency response. The behavior of single collapsing bubble agrees qualitatively with previous experimental results, and it is shown that the present experimental method is effective in investigating the bubble collapse and generation of impulsive pressure. The speed of a microjet within the bubble is estimated to be about 100 m/s, or about ten times as much as that of a microjet penetrating the other side of the bubble surface. In the case of double collapsing bubbles the direction of microjet formation is different from the case of single bubble collapse.
The Japan Society of Mechanical Engineers, 日本語
DOI：https://doi.org/10.1299/kikaib.56.1583DOI ID：10.1299/kikaib.56.1583,
ISSN：0387-5016,
CiNii Articles ID：110002388993 衝撃波による複数空気泡の崩壊に関する一実験 杉山 弘; 田中 徹男; 小原 哲郎; 干場 紀樹; 奥田 教海
日本機械学會論文集. B編,
巻：53,
号：495,
開始ページ：3141,
終了ページ：3145, 1987年
An experimental study was made on the collapse of multiple air bubbles by a shock wave using a water shock tube and a high speed camera. High speed schlieren photographs show the processes of a high pressure region formation or of shock wave formation near multiple air bubbles when they rebound. Two impulsive pressures, 0.72 and 1.75 MPa, were applied to multiple air bubbles with an initial radius of about 1.2 mm. It is shown that in the case of impulsive pressure 1.75 MPa, the multiple air bubbles produce weak shock waves around themselves when they rebound.
The Japan Society of Mechanical Engineers, 日本語
DOI：https://doi.org/10.1299/kikaib.53.3141DOI ID：10.1299/kikaib.53.3141,
ISSN：0387-5016,
CiNii Articles ID：110002401041 衝撃波による複数空気泡の崩壊に関する一実験 杉山 弘; 田中 徹男; 小原 哲郎; 干場 紀樹; 奥田 教海
日本機械学会論文集 B編,
巻：53,
号：495,
開始ページ：3141,
終了ページ：3145, 1987年
An experimental study was made on the collapse of multiple air bubbles by a shock wave using a water shock tube and a high speed camera. High speed schlieren photographs show the processes of a high pressure region formation or of shock wave formation near multiple air bubbles when they rebound. Two impulsive pressures, 0.72 and 1.75 MPa, were applied to multiple air bubbles with an initial radius of about 1.2 mm. It is shown that in the case of impulsive pressure 1.75 MPa, the multiple air bubbles produce weak shock waves around themselves when they rebound.
The Japan Society of Mechanical Engineers, 日本語
DOI：https://doi.org/10.1299/kikaib.53.3141DOI ID：10.1299/kikaib.53.3141,
ISSN：0387-5016,
CiNii Articles ID：110002401041
