著者

竹島 敬志 藤井 照重 竹中 信幸 浅野 等

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.66, no.646, pp.1467-1472, 2000-06-25

被引用文献数

1

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An experimental study has been carried out to clarify the characteristics of the void fraction and liquid film thickness of air-water two-phase flow in vertical tubes of 25 mm inside diameter with wire coil of varying wire diameter and pitch. Flow pattern in the experiment of average void fraction and local void fractrion distribution in a cross section is bubble flow, and liquid film thickness is in the region of semi-annular and annular flow. It is clarified from these experiments that the average void fraction in tubes with a wire coil is lower than that of the smooth tube and decreases with the wire diameter owing to the centrifugal force of swirl flow which concentrates bubbles at the center of the tube, and the liquid film thickness between the wire coil is uniformed with the decrease of the pitch of wire coil and that liquid film becomes thicker after the passage of wire coil with the increase of the wire diameter.

著者

林 農 加藤 優 田川 公太朗 原 豊

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 B編 (ISSN:03875016)

巻号頁・発行日

vol.74, no.740, pp.841-849, 2008-04-25 (Released:2011-08-16)

参考文献数

11

被引用文献数

1

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In recent years, the wind turbines have been installed actively and the suitable sites of wind farm have been decreased on land. On the other hand, a lot of wind energy resources are latent and it is expected that wind power will be installed in the future on the sea. This study aims to establish a measurement method of wind characteristics using a small ship for decision of suitable site for offshore wind power. We constructed the wind measurement system, which is composed of an ultrasonic anemometer, a differential GPS (DGPS) and an inertial measurement unit. The system was installed to a small ship and wind characteristics at 10 m height above the sea surface were measured by an ultrasonic anemometer on the Sea of Japan close to Tottori prefecture. Raw data of the wind velocity obtained in the proposed method includes the error caused by the pitching, rolling and yawing of the ship. In this study, the raw data of wind velocity was corrected by the data of the DGPS and the inertial measurement unit. Conclusively, the raw wind velocity contaminated by the oscillation and cruising of the ship was corrected and the wind velocity maps were obtained.

著者

石井 俊夫 岸本 健 永田 勝也

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.50, no.449, pp.151-158, 1984-01-28

被引用文献数

2

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ヘルムホルツ形燃焼振動をしている燃焼器に膨張形消音器および共鳴器消音器を付設して、それぞれの燃焼に及ぼす影響について議論し、また、音響インピーダンスの配分をばね-質点系モデルの上で実現し、配分割合の周波数依存性をテコ-コロを用いて摘用させた。その結果十分精度あるモデル化ができ、このタイプの消音器設計に有意な寄与できる方法を確立した。

著者

許斐 敏明 佐々木 洋二郎

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.71, no.705, pp.1428-1435, 2005-05-25

被引用文献数

22

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A technique to be able to improve efficiency of PEFC (Polymer Electrolyte Fuel Cell) has been investigated by classification into over voltages. Effects of running condition on it were surveyed by using this technique. Results show that dry condition at MEA makes cathode activation and IR over voltage increase, and that wet condition increases cathode concentration over voltage caused by flooding. It is proved this technique could be able to obtain best running condition in trade off and to improve efficiency of PEFC.

著者

新井 雅隆 樋口 豪 廣安 博之

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.50, no.453, pp.1345-1352, 1984-05-24

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軽油および複合燃料によるディーゼル噴霧の着火おくれを定容燃焼器を用いて測定した。この際、着火おくれは発火おくれとし、これをフォト・トランジスタにより検出した。測定結果をアレニウス表示したところ、高温側と低温側に分かれた2本の直線になることがわかった。またエタノール混合軽油で約50%以下、水-軽油エマルジョンで約40%以下の混合割合であれば、着火おくれは軽油の場合と大差のないことがわかった。

著者

笹原 俊雄 山崎 慎三 富田 幸雄

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.46, no.404, pp.673-683, 1980-04-25

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再生形にて主として送風機内部流れおよび性能と機械諸要素との関係を実験的に研究し,さらに粘性を変えて実験したポンプの場合も含めて検討し,つぎのことを明らかにした.(1)内部流れと機械諸要素の関係は送風機およびポンプととも類似の傾向を示し,性能諸係数も同じ無次元数で概略の整理が行える.(2)流路の断面内および全区間にわたって羽根角度が異なる送風機の内部流れを調べ,特に逆流が性能曲線の特長と密接に関係する.

著者

辻 義之 宮地 圭 鈴木 孝裕 中村 育雄

出版者

日本機械学会

雑誌

日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B (ISSN:03875016)

巻号頁・発行日

vol.70, no.695, pp.1679-1686, 2004-07-25

参考文献数

17

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In a zero-pressure gradient turbulent boundary layer, the multi-point measurement by 24 ch I-probes is performed. The relation between coherent structures and logarithmic velocity profile is studied by way of proper orthogonal decomposition technique and the stochastic estimation. It is found that the existence of coherent structures are necessary condition for the universal velocity profile, however it is not enough. Small-scale motions are also necessary to realize the log-law profile. The probability density profile in the overlap region is studied, and as a result, the invariant assumption of PDF in relation to the coherent structure is obtained. It was also evaluated how the velocity fluctuation in the log-region is affected by the coherent structures.

著者

藤居 達郎 西口 章 福島 敏彦 大内 富久 功刀 能文

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.61, no.587, pp.2683-2689, 1995-07-25

被引用文献数

1

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This paper presents an experimental validation of the mathematical model of an evaporator and absorber, which are components of a water/lithium-bromide absorption chiller heater. The experimental cycle employs a gas-fired, 176 kW (50 RT) machine, which is mainly used in individually distributed air conditioning systems. One of the features of this model, described in the 1st report, is prediction of both static and dynamic characteristics of the machine, especially transient response to rapid change in external conditions. In this experiment, an immediate change in chilled water flow rate is the input signal. Output signals for comparison with predicted data are transient responses of chilled water outlet temperature, evaporating pressure and cooling capacity derived from chilled water temperature and its flow rate. From comparison between experimental data and values predicted using the model, steady-state analytical error is less than ±3%, and dynamic behavior can be predicted within ±10% analytical error of response time.

著者

金山 公夫 馬場 弘 山本 政樹

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 B編 (ISSN:03875016)

巻号頁・発行日

vol.54, no.499, pp.p728-733, 1988-03

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The renewable energy laboratory of Kitami Institute of Technology is a facility for the research of space heating, cooling and hot water supply using solar energy and underground water heat by means of a solar system and a heat pump system. Measurements for two types of combination of series-and parallel-solar heat pump systems has been carried out during the last five years. In this study, based on the measured data of the solar heat pump systems, a simulation program is produced to estimate the thermal performance of the systems, and the results calcuated by a personal computer are compared with the experimental results. The correlation between two dimensionless factors of X_H(=COP_<HP>Q_<EMAX>/Q_<TL>) and Y_H(=F_W/F_<WMAX>) can be obtained in order to calculate easily the performance of a stand along heat pump system.

著者

黒川 淳一 森川 薫博

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.51, no.467, pp.2076-2083, 1985-07-25

被引用文献数

15

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円管内の加速・減速流れにおける速度分布,遷移および管摩擦係数に及ぼす加速度の影響をおもに実験的に検討した.その結果,粘性の伝ぱ速度に対して加速が大の場合と小の場合では断面速度分布および遷移レイノルズ数が著しく異なり,層流加速域と乱流加速域では管摩擦係数の傾向が異なること,および減速流れではほぼ全期間を通じて乱流状態が保持され,管摩擦係数は準定常値より大きくなることなどを明らかにした.

著者

古川 明徳 曹 銀春 大熊 九州男 眺野 貴裕 渡邊 聡

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.67, no.657, pp.1184-1190, 2001-05-25

被引用文献数

11

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Demands for higher performance of axial flow pumps have led pump designers to consider the creative strategies for the new type. As a solution, contra-rotating rotors might be applied to a pump. Comparative experiments were conducted for two types, consisting of contra-rotating rotors and a rotor and a stator respectively, which were designed under the same specifications of pump head, flow rate and rotor specific speed. The measured pump performances and flow distributions are shown and the advantages of using contra-rotating type are clarlfied as follows. Contra-rotating type is superior in pump efficiency and cavitation performance in range of partial flow rates to conventional one though the specified pump head and maximum efficiency were not satisfied at design point in the case of contra-rotating test rotors. Results demonstrate that the rear rotor design is important to improve the pump efficiency.

著者

富山 明男 平野 雅司 松田 隆男 坂口 忠司

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.58, no.551, pp.2177-2183, 1992-07-25

被引用文献数

1

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Computational time for numerical simulation of transient incompressible viscous flow is governed by numerical methods to solve the Poisson equation of the pressure. In order to improve the computational efficiency of the SOR method, a mathematical analysis was conducted in the present study to derive the spectral radius, i. e., the maximum modulus of the eigenvalues of the iteration matrix for a discrete Poisson equation in staggered mesh system. The derived spectral radii for the point, line and area Jacobi iteration matrices are applicable to the Dirichlet, the mixed boundaryvalue and the Neumann problems in an n-dimensional rectangular region. The validity of the optimum relaxation parameter of the SOR method, which was calculated by the derived spectral radii, was confirmed by numerical experiments. Furthermore, a simple estimation method of the optimum relaxation parameter for the non-rectangular region was presented for transient flow analyses.

著者

杉井 康彦 西尾 茂 岡本 孝司 中野 厚史 南山 求 新見 英幸

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 = Transactions of the Japan Society of Mechanical Engineers. B (ISSN:03875016)

巻号頁・発行日

vol.70, no.691, pp.701-706, 2004-03-25

参考文献数

18

被引用文献数

2

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Blood flow in microvessels, such as arterioles, capillaries and venules, whose diameter ranges from 5 to 50μm, is responsible for the maintenance of tissue and organ functions. The measurement of microvascular blood flow velocity with high measurement accuracy is essential for basic and clinical studies in the assessment of flow shear stress at the vascular wall in relation to substance exchange between blood and tissue. This paper aimed to evaluate the velocity field of blood flow in microvessels with high spatial and temporal resolution. By using micro PIV system, the velocity distributions of red blood cells flowing in rat mesenteric arterioles, including near the wall in the axisymmetric plane, were obtained. Ensemble averaged time-series of velocity profiles in the cross-sections were calculated for comparison. It was shown that the arteriole velocity profile was blunt in the center region of the vessel cross-section while it was steep in the near wall region.

著者

田辺 誠一 山口 雄三 横山 俊昭 高木 武夫

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.51, no.464, pp.1147-1156, 1985-04-25

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高比速度フランシス水車ランナの出口流れを非定常流れ計測用のピトー管を使って測定し,ランナ出口部におけるベーン間の流れのようすを明らかにした.特に,油膜流跡実験結果と対比させて検討することにより,ランナベーンの後流部やベーン負圧面に逆流が発生した時の流れのようすを明らかにした.

著者

眞下 伸也 仲津 英治 青木 俊之 松尾 一泰

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.62, no.597, pp.1847-1854, 1996-05-25

参考文献数

23

被引用文献数

6

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Compression waves generated by a high-speed train entering a tunnel were measured in three Shinkansen tunnels and the results were compared with the numerical values calculated using the TVD scheme. The strength of a compression wave is exponentially attenuated with distance as it propagates along the tunnel in both slab and ballast track tunnels, and the attenuation in the ballast track tunnel is considerably larger than that in the slab track tunnel. In the slab track tunnel, the compression wave is steepened as it propagates, while it spreads in the ballast track tunnel. The criterion for judgment whether the compression wave is steepened or spreads is expressed by the value of acoustic Reynolds number of about l0〜15.

著者

西田 修身 向原 誠也

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.49, no.441, pp.1068-1077, 1983-05-25

被引用文献数

6

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燃焼によって発生するすす(固体の微粒子)は大気汚染の大きな原因で,その低減が緊急課題である.そこですすの生成・分解および排出状況を把握することは重要である.本報ではプロパン・空気系の軸対称層流拡散火災について,レーザ光散乱・透過法を用いて,すす粒子径,数密度および体積濃度分布を測定し,同時にすす重量濃度,ガス温度および各種組成濃度をも測定した結果と対応させて,種々検討をした.

著者

奥村 幸彦 岡崎 健

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.73, no.731, pp.1434-1441, 2007-07-25

被引用文献数

3

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This paper reports on the pyrolysis and CO_2-gasification of various biomass materials in a pressurized thermobalance. In particular, the primary yields of total volatiles, tar and non-condensable gases, together with the composition of non-condensable gases, are measured as a function of temperature at 1 atm and 10.8 ata. The use of a high-intensity infrared heating source, in conjunction with a non-absorbing carrier gas (viz. argon), is reported to reduce the significance of secondary gas-phase pyrolysis reactions. Linear trends with atomic H/C ratio are observed in the tar yield, total volatile yield and CH_4 yield during pyrolysis. The gasification kinetics of biomass chars (pyrolysed to 700℃ at a medium heating rate) have also been measured by measuring the rate of weight loss during reaction with CO_2 as a function of temperature. First-order kinetic rate constants are then determined by fitting the weight loss data using a random pore model. The results indicate that the reactivity of the biomass materials is intermediate between lignin and cellulose and that they are much more reactive than a black coal char.

著者

奥村 幸彦 金内 健 岡崎 健

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.71, no.702, pp.702-710, 2005-02-25

被引用文献数

1

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The coal-pyrolysis experiment under elevated pressure conditions using a pressurized ther-mobalance has been carried out to clarify the mechanisms and the processes at conditions changing from normal pressure to higher pressure (10.6 ata) and from slow (0.1 K/s) to rapid heating rate (20 K/s). Simultaneously, a new pyrolysis model which can describe a pressure effect on the evolution behavior has been developed based on the FLASHCHAIN^[○!R] model including a quantitative estimation of the volatilized gases and released tar vapor. From the experiment, the tar vapor formation is suppressed and the yields of CH_4 gas shows increasing behavior at higher pressure conditions. Because the mole fraction of tar vapor decreased with the increase of the pressure by Raoult's law, and the recombination reactions of remaining metaplast (precursor of tar) within the coal are activated, resulting in more chars and more gas yields (CH_4, CO_2). At rapid heating rate conditions, the conversion from the metaplast to the volatile matter would be more active, because the reaction temperature range for thermal pyrolysis shifts to higher range with increase of heating rate. It was found that the rapid heating rate affects the molecular structure of the coal substantially.

著者

媚山 政良

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.53, no.495, pp.3358-3362, 1987-11-25

被引用文献数

12

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The author and his co-workers have been developing the technique of collecting, conserving and utilizing systems of cold heat energy in the winter season. This paper presents an example of methods for the storage of agricultural products by the use of natural ice in winter season ; that is, by means of a HIMURO type storage shed. The author has proposed a method for the thermal design of a cold storage room taking account of monthly changes in environmental conditions and heat generation from agricultural products. The experiment was performed over a period of one year to verify the propriety of the thermal design and to observe the storing condition of product by using a HIMURO type storage shed on a practical scale. The close agreement between the observed and designed characteristic values were obtained. It is clear that the characteristics of the HIMURO type storage shed are very suitable for storing many kinds of agricuitural products over a long time period.

著者

佐藤 正隆

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.47, no.420, pp.1604-1611, 1981-08-25

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エントロピに負号を付けるという, ネゲントロピの従来の定義は, 情報や秩序, 非平衡性, 仕事などを統一した概念としてとらえるには不十分であった. 本研究では従来の定義に変更を加えた新しい定義を提案し, 上記の諸概念をより適切に表現できる量を導いた. これによってネゲントロピと仕事との密接な関連が示され, この方向は有効なエネルギなどへもつながるが, 本報ではこのような展開のための基礎概念の定式化を行っている.