著者

松岡 常吉 中村 祐二

出版者

日本実験力学会

雑誌

実験力学 (ISSN:13464930)

巻号頁・発行日

vol.20, no.4, pp.229-236, 2021-01-07 (Released:2021-01-14)

参考文献数

12

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Scale modeling based on static and dynamic similarity has been widely used with high-speed photography techniques for motion pictures to reproduce unrealistic world. Focusing on video works created by SFX as examples of scale modeling experiments, this paper attempts to explain the scale modeling theory, so called “Law approach” which is a method to derive the scaling law based on deep physical insights. To accomplish this, the falling motion of an object in fluid is taken up as the simplest but frequent case. The governing equation of the phenomenon is considered, and the magnitude of each term is estimated. A quantitative comparison demonstrates which factor is most significant in that phenomenon. Though it seems a relatively complicated explanation, it is believed that this approach gives a clear insight into how the dominant factor(s) is extracted in the Law approach.

著者

松岡 常吉 中村 祐二

出版者

日本実験力学会

雑誌

実験力学 (ISSN:13464930)

巻号頁・発行日

vol.20, no.4, pp.229-236, 2021

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<p> Scale modeling based on static and dynamic similarity has been widely used with high-speed photography techniques for motion pictures to reproduce unrealistic world. Focusing on video works created by SFX as examples of scale modeling experiments, this paper attempts to explain the scale modeling theory, so called "Law approach" which is a method to derive the scaling law based on deep physical insights. To accomplish this, the falling motion of an object in fluid is taken up as the simplest but frequent case. The governing equation of the phenomenon is considered, and the magnitude of each term is estimated. A quantitative comparison demonstrates which factor is most significant in that phenomenon. Though it seems a relatively complicated explanation, it is believed that this approach gives a clear insight into how the dominant factor(s) is extracted in the Law approach.</p>

著者

後藤 武史 稗田 寛 山中 健輔 中村 祐二 宮城 成圭 古賀 裕

出版者

West-Japanese Society of Orthopedics & Traumatology

雑誌

整形外科と災害外科 (ISSN:00371033)

巻号頁・発行日

vol.32, no.3, pp.755-758, 1984 (Released:2010-03-16)

参考文献数

9

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In crystallographic study of tophaceous substances and deposits in gouty synovial fluids using differential-interference microscopy, polarized light microscopy and X-ray diffraction method, the following results were obtained.1) Substances of subcutaneous tophi and deposits in gouty synovial fluids were found to be needle-like crystals. By polarized-light microscopy, they were negatively birefringent with extinction on the long axis.2) The needle-like crystals obtained from subcutaneous tophi and/or synovial fluids in gouty patients have been positively confirmed as monosodium urate monohydrate (NaC5H3N4O3·H2O) by X-ray diffraction technics.

著者

中村 祐二 松岡 常吉

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.60, no.192, pp.75-82, 2018 (Released:2019-02-15)

参考文献数

16

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Resonance behavior of twin flickering (non-premixed) flames at various separation distances horizontally is examined and two oscillation modes (in-phase and anti-phase) are clearly identified depending on the distance. Our ultimate goal is to develop the acceptable mathematical model to explain such resonance behavior. There has been proposed “radiation-basis” mathematical model by physics-oriented researchers, claiming that the radiation is a primary factor to give an anti-phase mode. Our recent experimental and numerical studies, on the other hand, suggest that the radiation may not be the essential factor, rather, fluid dynamical motion shall be a key factor to cause the mode transition. Potential strategy to upgrade the mathematical model are proposed. Taking a “mathematical-scientific” approach to combustion problem is typical inter-disciplinary issue and productive interaction between physicists and combustion researchers is found to be highly recommended to develop further.

著者

山崎 貴史 松岡 常吉 横山 博史 中村 祐二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.86, no.889, pp.20-00210, 2020 (Released:2020-09-25)

参考文献数

25

被引用文献数

1 1

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The effects of the traveling sound wave generated by the speaker on diffusion flame were investigated experimentally. The sound frequency was varied from 50 to 1000 Hz using two sizes of loudspeakers, whose peak frequency showing the maximum sound pressure amplitude is nearly identical. A spirit lamp was used as the reference (diffusion) flame. Having irradiation of sound, the flame was inclined and stretched toward the traveling direction under specific range of the exposed frequencies and importantly, the effective range of the frequency was found to be quite different in two speakers used in this study. Precisely speaking, the deformed flame length reached its maximum value under the condition of 200 to 400 Hz for small speaker and 50 to 200 Hz for large speaker, respectively. In addition, the velocity distribution around the speaker was measured to reveal that the variation of flame length with respect to frequency, and it was found that the response against the applied frequency was rather close to that of flow velocity, not that of the acoustic pressure amplitude. Further investigation of flow field nearby the speaker clearly showed that the pump-like flow acceleration was induced by the periodic motion of the membrane of the speaker. From the above results obtained, it was confirmed that the effect of acoustic sound on the flame shall be come not only from pure acoustic wave feature but also from the factors depending on the hardware. Without the eliminating the latter effect, nature of acoustic-flame interaction behavior by using acoustic characters (e.g., frequency or acoustic pressure) is not readily available.

著者

鎌田 祐一 平沢 太郎 中村 祐二

出版者

社団法人 可視化情報学会

雑誌

可視化情報学会論文集 (ISSN:13465260)

巻号頁・発行日

vol.29, no.9, pp.35-41, 2009 (Released:2009-09-30)

参考文献数

7

被引用文献数

4 2

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マルチピーク型光学フィルターとカラーCCDカメラを組み合わせた熱画像カメラを用い、近赤外線における2色法による温度分布の可視化を行った。本方式では従来型の2色法と比べてより低温域(>500℃)を高解像度で計測が可能である。試作した熱画像カメラは1000℃近傍によって、空間解像度10μmで3℃、300μmで0.2℃の繰り返し精度(1σレベル)を達成する事ができた。

著者

松岡 常吉 村上 智志 山崎 拓也 中村 祐二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.852, pp.17-00009-17-00009, 2017 (Released:2017-08-25)

参考文献数

29

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This paper numerically investigated the detail process to appear the asymmetrically spreading flames in narrow channel consisted of combustibles. We have successfully reproduced the transient process to form asymmetrically arranged spreading flame first ever in this work. 2-D, time-dependent mass and energy transport process as well as one-step chemical process in gas-phase is considered. Thick solid combustible plates (PMMA) are placed at both sides, then exactly the same ignition operation is made to initiate symmetrical processes. Pure oxygen is fed into the channel at the fixed rate to promote the spreading. Oxidizer velocity and channel height are varied as numerical parameters in this study. After the forced ignition, the combustibles are pyrolized via one-step reaction to evolve the fuel gas into the gas phase to form the opposed-mode flame spreading. Results show the distinctive three spreading modes (two-symmetric flames spreading, two-asymmetric flames spreading and one flame spreading) and transient process from one to the other mode is successfully simulated, which is hardly achieved in experiment. The asymmetric flame spreading mode appears under the limited combination of channel height and velocity. Moreover the distance between two leading edges of the flame varies depending on the imposed condition. Flow patterns are found to be sinus motion, thus the heated and accelerated oxidizer flow may enhance the reaction in the downstream. In this way, it is suggested that the flowing oxygen is effectively used to burn two fuel slabs. It is obvious that the asymmetrical configuration gives temporary stable condition. To study the details further, systematic study is demanded.

著者

横山 徹 三木 信弘 小川 吉彦 正木 信夫 島田 育廣 藤木 一郎 中村 祐二

出版者

一般社団法人電子情報通信学会

雑誌

電子情報通信学会技術研究報告. SP, 音声

巻号頁・発行日

vol.98, no.557, pp.57-64, 1999-01-22

被引用文献数

2

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我々は, 声道の3次元形状を考慮した音声生成モデルの構築を目的として, 断層画像群を基に3次元声道形状のワイヤフレームモデルを構成する方法を提案した.そして声道形状を1次元縦続音響管モデルに近似することで声道伝達特性を推定した.しかし上記の変換の過程には多くの不確定な要素が含まれており, これらが伝達特性にどのように影響するかについての検討は成されていない.本稿では, その中でも特に音響的に影響すると考えられる要素として, 音波伝搬経路のずれ, およびセクション数の違い, および口唇形状を考慮することによって, 主要フォルマント周波数にどのような影響が出るかについて検討を行う.

著者

竹野 忠夫 中村 祐二 朱 学雷 西岡 牧人

出版者

名古屋大学

雑誌

基盤研究(B)

巻号頁・発行日

1998

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現在,大きな環境問題の原因として挙げられるすすに関して,その生成機構および抑制方法は見つかっておらず,未だ不明な点が多い.すすはNOxと並ぶ2大燃焼排出物であり,火炎中のその生成機構を理解することは我々人類にとって重要な課題である.これまでの研究報告によれば,すすはその前駆物質であるPAH(多環芳香族炭化水素)からできるとされているが,PAHの生成機構さえも十分に理解されていない部分が多い.そこで本研究では,対向流拡散火炎中を対象として,数値計算および実験を通じてPAHの生成機構を理解することを目的とする.まず平成10年度においては,約100種の成分と正逆500組の素反応を考慮したHai-Wangにより開発された化学反応機構を用いた数値計算により,PAHの中で最も重要な働きを示すベンゼン生成に関する知見を得た.その結果,C3系の反応物がPAHの基であるベンゼン環の生成に最も顕著であることがわかった.平成11年度においては,対向流拡散火炎中のベンゼンおよびその生成に関わると言われているC3系およびC4系の成分に着目し,それらの濃度測定をGC/MS(ガスクロマトグラフィー/質量分析計)を用いて行った.また得られた実験結果と数値計算で得た知見との比較・検証を行った.その結果,数値計算ではベンゼンおよびC3,C4系炭化水素の量を約半分以下にしか見積もらないことがわかった.また,ベンゼン生成領域は数値計算よりも定温領域に移り,それがすす発生に関係した影響であることも指摘できた.しかしGC/MSで得られる情報もまだ十分ではないので,上記で推測されたすす生成に関する物理を確実に述べるには,実験装置の工夫,または数値計算において別の反応モデルを用い,より総合的な評価をする必要がある.

著者

高橋 真一 中村 祐二 山下 博史 鎌田 祐一 矢野 賢司 橋本 みゆき 伊藤 誠

出版者

一般社団法人日本機械学会

雑誌

熱工学コンファレンス講演論文集

巻号頁・発行日

vol.2004, pp.59-60, 2004-11-10

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In this paper, a dependence factor of soot emissivity on wavelength, a is studied in a counterflow propane diffusion flame by spectroscopic measurement. The spectrometer is set vertically to the nozzle and radiation of luminous flame is obtained each height from the lower burner. The emissivity is calculated from emissive power of luminous flame and blackbody furnace, and a is obtained by analysis of the emissivty. The relations between a and temperature, wavelength and distance from lower burner are examined. Results show that a is smaller with longer wavelength in the range of 600nm - 1000nm. Additionally, it is suggested that a also depends on soot conditions.