著者

西 義久 木下 泉 西村 聡

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.70, no.691, pp.715-722, 2004-03-25 (Released:2011-03-03)

参考文献数

17

被引用文献数

2

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The experiments about the gas lift pump in lead-bismuth eutectic are performed with risers of three kinds of diameters [φ 69.3 mm (SD case), φ 106.3mm (MD case), φ 155.2mm (LD case)]. The main results are as follows : (1) The coefficient of the drift flux model was derived from the experimental results. (2) The LBE flow rate obtained from the design method based on water/gas system with the relation of the drift flux model corresponds to the experimental results obtained in the MD and the SD cases. It is considered that the evaluation method can be used for the LBE gas lift pump in a small diameter riser. (3) In the LD, the design method excessively evaluates the lead-bismuth circulating flow rate. It thought that the circulation head will not occur in the experimental loop. The following factors are considered to be the causes of this the three-dimensional behavior of bubbles becomes significant, and the local descending flow is generated in the riser when the riser diameter increases.

著者

松野 善之 小玉 恭弘

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.66, no.645, pp.1380-1383, 2000-05-25

参考文献数

6

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Viscosity of magnetic fluid changes when an interaction angle between magnetic field and flow vorticity changes. The test shows that viscosity becomes maximum when they cross perpendicularly and becomes minimum when they are parallel. These phenomena were studied theoretically by M. I. Shliomis and W. F. Hall. This paper describes an analysis of the relation between viscosity and the interaction angle from test results and the comparison between that and the theory.

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.51, no.464, pp.1235-1242, 1985-04-25

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著者は以前従来のネゲントロビの定義を変更してエントロビ差による定義を提案したが,これは孤立系に基づくもので,一般の状況下にある系に適用するには更に定義の変更が必要になる.本報ではKullback-Leiblerの情報量による定義を提案し,これによるネゲントロビが正値性や非平衡性,仕事の可能性を表すことを示し,さらにエクセルギを導くことを見た.拡張されたネゲントロビは,その一部として拡張前の懸念を含んでいる.

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.53, no.493, pp.2863-2868, 1987-09-25

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The capacity of negentropy is the maximum negentropy that a system can have. For example, the negentropy contained by a cylinder-piston system becomes larger as the piston is moved inward, but practically it has a maximum, namely, the capacity of negentropy. Generally, capacity represents a certain type of macroscopic order (capacity-type of order) which comes from the relation between molecules, and without this type of order, negentropy cannot beheld by a system. Capacity-type of order is regarded as a pattern which has the property of recovering its origin in thermodynamic situations, and the order may be destroyed by negentropy which exceeds the capacity. Although nonequilibrium-type of order, which is represented by negentropy, differs from the capacity-type of order, they are intimately related with each other. The general definition of the capacity is made in a statistical-mechanical manner based on negentropy defined by Kullback-Leibler information.

著者

許斐 敏明 石山 忍

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.48, no.434, pp.2127-2133, 1982-10-25

被引用文献数

1

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エンジンのシリンダ内圧力, 正味トルク, クランク角速度からサイクル内摩擦トルク変化を計測することを試みた. これに必要な高精度角速度計, および多気筒のシリンダ内圧力と回転数を同時に時系列に記録できる解析装置, 両者を開発した. これらを用いた実験から, この方法は従来の平均値のみの計測よりも多くの知見が得られることおよび駆動系のねじり振動解析におけるエンジン減衰係数の測定にも利用できることがわかった.

著者

武田 好央 中込 恵一 新村 恵一

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.62, no.599, pp.2887-2894, 1996-07-25 (Released:2008-03-28)

参考文献数

6

被引用文献数

5 8 8

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There is a gradient of fuel concentration in the spray of conventional direct-injection diesel engines. Therefore, a region of stoichiometric mixture ratio exists in the injected spray and a high concentration of NOχ is produced. In this study, fuel injection timing was widely advanced to promote the mixing of fuel and air. Using this injection method, the engine could be driven with premixed lean diesel combustion (PREDIC), and NOχ emissions were greatly reduced. To avoid the fuel spray contacting the cylinder liner, the fuel was injected by two side injectors simultaneously. The two sprays from the side injectors collided with each other and remained in the center region of the cylinder. Thus mixing of fuel and air was promoted by a long ignition delay period. In the case of conventional injection methods, NOχ could not be reduced to under 400ppm (λ=2.7). In contrast, in the case of PREDIC, NOχ emissions were reduced to as low as 20ppm (λ=2.7).

著者

須賀 一彦

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.70, no.697, pp.2386-2393, 2004-09-25

被引用文献数

1

---

Modeling the pressure-diffusion process is discussed to improve the prediction of turbulent recirculating flows by a second moment closure. Since the recent DNS research of a turbulent recirculating flow suggeted that the pressure-diffusion process of the turbulence energy was significant in the recirculating region, the present study focuses on the rapid part of the process consisting of the mean shear. This rapid pressure-diffusion model is developed for the Reynolds stress equation using the two-component limit turbulence condition and added to a low Reynolds number two-component-limit full second moment closure for evaluation. Its effects are discussed through applications of turbulent recirculating flows such as a trailing-edge and a back-step flows. Encouraging results are obtained though some margins to be improved still remain.

著者

庄司 正弘 涌永 隆夫 児玉 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.50, no.451, pp.716-723, 1984-03-28

被引用文献数

3

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噴霧冷却の基礎研究として、均質、単一の液滴列(サブクール液滴)を用い、特に高加熱面温度領域(非ぬれ領域)の伝熱特性につき実験的に研究した。その結果、熱伝達は加熱面温度によらず一定となること、液サブクールに比列して増加すること、液滴1個当たり伝熱量qは液滴の体積に比例し、液滴速度にほとんどよらないこと、qに関するデータは実用的な次式でよくまとまることを示した。q=π/(12)d^3ρcΔT_<SUB>

著者

親川 兼勇 屋我 実 那須 謙一 瀬名波 出 松田 昇一 安座間 工

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.63, no.607, pp.979-985, 1997-03-25

被引用文献数

4

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Heat transfer characteristics and flow patterns were measured over the plate for various separation distances between the nozzle exit and target plate when the air issuing from a sharpedged cross-shaped nozzle impinges on the plate. The local heat transfer coefficients in the radial direction for different circumferential positions were calculated using the wall temperatures measured by means of thermocouples, and the flow patterns were observed using a oil-titanium IV oxide method. The isotherms of the infrared images were also measured using an infrared radiometer with a two-dimensional array of InSb sensors. The geometric axes were switched due to the self-induced velocity of a vortex filament ; the convex corners became flat and the concave corners generated outward ejection. The distribution of the iso-heat-transfer-coefficient contours corresponds well to the flow pattern and the isotherm contours. These contours extended diagonally and demonstrated the Andrew's cross pattern for the short separations, subsequently becoming the octagonal patten, and then becoming circular at large separations. The correspondence of the heat transfer characteristic to the flow behaviors, and the heat transfer mechanism were also described.

著者

河田 剛毅 前川 博 小林 睦夫 斉藤 北

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.57, no.540, pp.2812-2817, 1991-08-25

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Spanwise eddy diffusivity of heat was measured in a flat-plate turbulent boundary layer with a constant spanwise temperature gradient and different intensities of free-stream turbulence. Comparison was made with the usual kinematic eddy viscosity measured in parallel. According to the experimental results, the ratio of these eddy diffusivities is strongly influenced by the free-stream turbulence. However, in the vicinity of the wall, this ratio approaches a certain universal distribution which is independent of the intensity of free-stream turbulence.

著者

岡島 厚 大津山 澄明 永森 稔朗 中野 智仁 木綿 隆弘

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.65, no.635, pp.2196-2203, 1999-07-25

被引用文献数

19

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Flow induced in-line oscillation of a structure with a circular or rectangular section was experimentally studied by free-oscillation tests in a wind tunnel. Detailed data of response amplitude of various cylinders have been acquired in a wide range of the reduced mass-damping parameter (Scruton number), by free-oscillation tests of two-dimensional cylinder spring-mounted to oscillate as a rigid cylinder. Flow induced in-line oscillation of the cylinder is certified to have two types of excitation mechanism; one is the so-called wake breathing effect accompanied with a symmetric vortex street and the other is the vortex excitation at a half of the critical reduced velocity. Also a fixed splitter plate was mounted behind a cylinder to eliminate the vortex shedding of alternate vortices from the cylinder, after Aguirre's experiments, and the results were compared with those without a splitter plate. As a result, we can classify the flow induced in line oscillation of the circular or rectangular cylinder. For a circular cylinder and a square one, two types of excitation phenomena appear in each reduced velocity region, the thin rectangular cylinder with the side ratio b/h=0.4 suffers from the vortex excitation, and the elongated rectangular cylinder with the side ratio b/h=2.5, is subjected to the wake breathing effect accompanied with a symmetric vortex street. It is found that fluidelastic characteristics of two types of in-line oscillations are quite different; i.e., the response amplitude are very sensitive to the reduced massdamping parameter, during the in line oscillation with a symmetric vortex street, while the oscillation of vortex excitation are rather insensitive.

著者

西野 耕一 笠木 伸英 平田 賢 佐田 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.55, no.510, pp.404-412, 1989-02-25 (Released:2008-03-28)

参考文献数

13

被引用文献数

6 8

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A technique for measuring instantaneous, three-dimensional velocity components in liquid flows was developed using digital image processing system. This system consists of three TV cameras, a digital image processor, a stroboscope, a laser disk recorder and a 16-bit microcomputer. The three-dimensional displacements of fine particles suspended in the liquid are tracked by the TV cameras and recorded on the laser disk recorder. The recorded image data is later replayed and sent to the image processor, and the three-dimensional velocity field is automatically calculated on the microcomputer. Uncertainty intervals associated with the present technique are systematically evaluated. An unsteady laminar Couette flow between two concentric cylinders, of which the outer cylinder starts to rotate impulsively, is measured by the present technique. The instantaneous velocity profiles measured show good agreement with the analytical solutions within the experimental uncertainty, and thus, the present technique is proven to be applicable to the measurement of unsteady flow. The decay of turbulence generated in a stirred water tank is also measured in good agreement with the theoretical prediction.

著者

篠原 俊夫 松浦 祐太郎

出版者

The Japan Society of Mechanical Engineers

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.46, no.406, pp.1065-1073, 1980

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軸流タービンの内部効率向上のため,損失の大きなブレード先端部および根本部の流れについて翼列実験およびモデルタービン実験を行い,主流と損失流れとの相互関係を明らかにした.そして,翼先端および翼根本での反動度を買えた新しいフローパターンを考え,これをノズルをねじることにより実験して,従来系との比較実験を行った.その結果1%以上のタービン効率の上昇を確認した.

著者

大塚 芳郎 北野 三千雄

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.48, no.433, pp.1818-1825, 1982-09-25

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円管内層流拡散炎のすす限界を, 燃焼管直径, 燃料管直径, 空気流速および燃料流速を広範囲に変化させて, メタン, エタン, プロパン, 正ブタン, アセチレンおよびエチレンの6種の炭化水素について測定した. すす限界は, 空気比λ, 燃料流量V_fおよび燃焼管直径によって支配され, すす限界直線の傾斜d log<λ/d log V_fの大小によって, すす限界はアセチレン形とメタン系に分けられ, 前者はすすの大粒子の, 後者は小粒子の微量化する限界である.

著者

安倍 賢一 長野 靖尚 近藤 継男

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.60, no.573, pp.1743-1750, 1994-05-25

被引用文献数

3

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We propose a new two-equation heat-transfer model which is modified from the model developed by Nagano, Tagawa and Tsuji (Proc. ASME/JSME Thermal Eng. Joint Conf., 3 (1991), 233). The main improvement is made by introducing the Kolmogorov velocity scale, u_ε≡(νε)^<1/4>, instead of the friction velocity u_τ, to account for the wall-limiting behavior. After investigating the characteristics of various time scales for the heat-transfer model, we employed a composite time scale which gives weight to a shorter scale among the velocity- and temperature-field time scales. With these modifications, it is shown that the present model quite successfully predicts the turbulent heat transfer in a boundary layer subjected to sudden change of heat flux, and in a separating and reattaching flow downstream of a backward-facing step.

著者

西村 智行 持丸 義弘

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.63, no.611, pp.2309-2315, 1997-07-25

被引用文献数

1 1

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A spectral finite difference method with domain decomposition is used to solve the Navier-Stokes equation for incompressible fluids. In the domain decomposition method, some subgrids consisting of multiple orthogonal curvilinear coordinate systems and of overlapping region (s) are adopted, and one-dimensional interpolation is applied to the overlapping region in the case of two-dimensional analysis to obtain neighboring values corresponding to a virtual boundary. Mass conservation on a virtual boundary is assured using a mass imbalance correction. Present numerical analyses for two-dimensional, internal, doubly-connected or triply-connected flow fields consisting of cylindric and elliptic boundaries show good consistency, accuracy and efficiency.

著者

佐藤 学 伊藤 勝宏 小野寺 収 高山 和喜 辻田 誠

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.55, no.509, pp.95-100, 1989-01-25

被引用文献数

1

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A new concept of a super charger for diesel engines is proposed and its performance is examined by TVD numerical simulation. The structure of the super charger has a simple duct-valve system which allows the feeding of compressed inlet air to the engine cylinder by an exhaust-gas driven chock wave. The two-dimensional unsteady flow of this duct-valve system was simulated by TVD numerical scheme applied to the Euler equations. It was found that the present supercharger has a performance which is preferable to low engine speed. The complicated wave interactions are simulated in detail.

著者

横堀 誠一 笠木 伸英 平田 賢

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.1029-1039, 1983-05-25

被引用文献数

3

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本論文は二次元衝突噴流のよどみ領域における流動構造および伝熱機構を実験的に明らかにしたものである.流れの可視化によってよどみ域は大きなスケールの乱流渦構造がスパン方向に非定常に発生することを明らかにしこれらの構造が自由噴流せん断部の渦糸の伸張から生じていることを示した.ついでにこの構造がよどみ点での伝熱促進に果たす役割について顕著な効果のあることを非定常温度場の可視化によって示した.

著者

清水 幸丸 村上 光清 葛原 定郎 永房 誠 杉野 公一

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.417, pp.729-738, 1981-05-25

被引用文献数

1

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本研究は, ディフューザの中心線がねじれS字状およびコイル状に曲げられた, いわゆる空間曲りデュフューザについて, その性能を調べたものである. このようなディフューザでは, 流入速度が通常の曲り管出口における速度分布のように二次流れを伴って不均一になっている場合には, この不均一流がディフューザの曲りと関連して, ディフューザ内に強い二次旋回成分を発生することとなり, はく離の発生が防止される. そして直線円すいディフューザよりも高い圧力回復効率を示すことを明らかにした.

著者

岩渕 牧男 立岩 幹雄 羽田 寿夫

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.48, no.432, pp.1501-1508, 1982-08-25

被引用文献数

2

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超臨界圧変圧運転ボイラでは, 火炉水管の冷却能力の面から従来スパイラリ・ワウンド形火炉構造が採用されているが, 垂直管形とすることにより本体支持構造の大幅な単純化が可能である. 本研究は, これに必要なライフル管の臨界圧近傍における伝熱特性を, 実際の超臨界圧変圧運転ボイラとほぼ同じ運転状態のもとで行われた試験結果にもとづいて述べたものである.