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.52, no.475, pp.1078-1085, 1986-03-25

---

Kullback-Leibler の情報量による定義を導入することによって、一般的な状況へ拡張されたネゲントロピの式を、本報では二つの異なる視点から展望した。第1の展開式からは交差項が得られる。交差項は系に課せられた前提条件を動かすことによって取り出しうるネゲントロピを表す。第2の展開式からは相互ネゲントロピが導かれるが、これは系を部分的に分割したとき、部分系相互間の非平衝性を表すものである。

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.51, no.467, pp.2132-2139, 1985-07-25

---

ネゲントロピを一般的な状況に適用できるように拡張する場合,エントロピ差でなくKullback-Leiblerの情報量によって定義すべきことを前報で述べた.本報ではこのネゲントロピと,置かれている状況下で系から取り出しうる最大仕事との関係を,例題について調べた.すなわちKullback-Leiblerの情報量によるネゲントロピと最大仕事とは,等温系においては比例し,等温系でない場合も両者の微少変化量をとれば比例する.

著者

尾関 高行 中垣 隆雄

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.76, no.763, pp.406-408, 2010-03-25

---

Electrochemical partial oxidation (EPOx) of methane can convert exhaust heat into electricity as much as difference between change of Gibbs free energy and change of enthalpy. In this paper, we considered 30kW power generation system combined Micro Gas Turbine and the Partial Oxdation Solid Oxide Fuel Cell using Gadolinium Doped Ceria as the electrolyte that has high oxide ion conductivity below 600℃. The cylindrical-shaped POSOFC is operated at 572℃ recovering turbine exhaust heat of 593℃ and accompanying production of hydrogen and carbon monoxide. According to the result of process simulation coupling with SOFC simulation including detailed polarization models, only addition of 16 liter POSOFC can increases the power generation efficiency by 8.5 points at fuel utilization of 80.1%.

著者

菅野 雅信 赤石 誉幸 山崎 由大 金子 成彦

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.76, no.763, pp.403-405, 2010-03-25

---

To realize stable operation of microgrids, gas engines require to compensate load changes from demands and variation of other renewable energy devices. Then, prehension of load following capability is important in gas engines. In addition, when biomass gas is supplied to gas engines, effect of fuel component variation on dynamic characteristics must be investigated, because components of biomass gas depend on operating condition of gasification or raw material. This study proposed a dynamic simulation model of gas engine and estimated transient response to load changes. Load changes were sinusoidal wave, and bias value, amplitude and frequency of them were varied. As a result, the frequency has more influence on transient response than the bias value and the amplitude. When biomass gas is supplied to gas engines, transient response is worce than city gas over the frequency of 0.1Hz.

著者

坂東 茂 幸田 栄一 笹嶋 賢一 柳井 崇 木下 守弘 沼田 茂生 緒方 隆雄 徳本 勉 浅野 浩志

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.76, no.763, pp.409-411, 2010-03-25

---

We developed the scheme of profitability analysis of a microgrid. The scheme consists of 4 processes. The first process is to calculate the optimal sizing of energy supply system in a microgrid by solving mixed integer non-linear programming by using the General Algebraic Modeling System (GAMS). The second one is to determine the distribution of system equipment by taking space in each area into account. The third one is to design electric equipment, such as transmission. The forth one is evaluation of pay-back time, reduction rate of primary energy consumption and that of carbon dioxide emission. By using this scheme we also evaluate pay-back time about construction of a microgrid in Tokyo.

著者

長井 浩 安藤 生大

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.76, no.763, pp.377-379, 2010-03-25

---

Wind turbines generate sustainable energy, however CO_2 is emitted during the various processes in the life cycle of a wind turbine. Therefore, it is important to take into account the latest data of the environmental impact in addition to applying megawatt scale wind turbines by the method of LCA. In this study, recent CO_2 basic unit (g-CO_2/kWh) was calculated under the conditions of that the life time of turbines is set to be 20 years and the life cycle includes manufacturing, construction, transportation and operation processes. The recalculation result of the domestic 2MW wind turbine constructed in Choshi area shows 10.8g-CO_2/kWh and 13.5g-CO_2/kWh under the conditions of average wind speed=6m/s, CO_2 emission rate of operation and maintenance=1.0%/year, the loss of transmission grid etc=5% in its life cycle. The important points of electricity produced by wind turbines are finding locations with good wind supply and application of large scale wind turbines. And the "product category rule" should be established for the standardized calculation of the Japanese CO_2 basic unit (g-CO_2/kWh) of the wind generator.

著者

山崎 哲 高本 正樹 細井 賢三 山崎 均 新井 悟司 清水 和義

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.642, pp.619-626, 2000-02-25

参考文献数

12

---

The partial flow dilution method is one of the typical measurement methods for particulate matter emission from diesel engines. In this method, exhaust gas at a transient flow rate should be transferred to a dilution tunnel at a constant ratio of exhaust gas. The present partial flow dilution method is used under steady-state engine operating conditions in lieu of direct flow rate measurement of exhaust gas. A more practical control of exhaust emission is, however, required world widely; therefore development of an exhaust gas flowmeter is indispensable in the partial flow dilution method for transient engine operating conditions. An ultrasonic exhaust gas flowmeter has been developed and been demonstrated to be capable of measuring the exhaust gas flow rate with sufficient accuracy.

著者

田中 創 山崎 博司 寺地 誠喜 瀬川 大資 角田 敏一

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.71, no.702, pp.690-695, 2005-02-25

参考文献数

10

被引用文献数

3

---

An experimental study has been carried out to reveal the statistical characteristics for the onset of micro-explosion of an emulsion droplet burning on a hot surface. Detail measurements of the waiting time for the onset of micro-explosion are made for various properties of base fuel, water contents and surface temperatures. The Weibull analysis is applied to obtain the distribution function of the waiting time for the onset of micro-explosion and to derive the empirical formula for the rate of micro-explosion as a function of water volume and emulsion temperature. The base fuels employed are n-decane, n-dodecane, n-tetradecane and n-hexadecane. The results show that the waiting time is correlated well with the Weibull distribution of the wear-out type. The mean waiting time decreases with an increase in the boiling point of base fuel, water content and surface temperature. An empirical formula is proposed for the rate of micro-explosion as a function of water volume and emulsion temperature.

著者

大森 修一 奈良林 直 森 治嗣 渡邉 史紀

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.75, no.751, pp.403-405, 2009-03-25

---

A Steam Injector (SI) is a simple, compact and passive pump. We are developing this innovative concept by applying the SI system for core injection system in emergency core cooling systems (ECCS) to further improve the safety of nuclear power plants. Passive ECCS in nuclear power plants would be inherently very safe and would prevent severe accidents by keeping the core covered with water (Severe accident-free concept). The passive core injection system (PCIS) driven by high-efficiency SI is a system that, in an accident such as a LOCA, attains a higher discharge pressure than the supply steam pressure used to inject water into the reactor by operating the SI. This report describes the experiments and the analytical simulation on a SI-driven PCIS for innovative-simplified nuclear power plant. In addition, we conducted the analytical simulations of SI, which grew in size for the actual nuclear power plant.

著者

山本 泰 武内 豊 白川 健悦 師岡 慎一

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.75, no.751, pp.397-399, 2009-03-25

---

In the envisioned high-power density core plant, the degradation of stability is concerned that is attributed to the shortening of rod heat conduction time constant upon the dense fuel grid and the increment of pressure drop caused by the wall friction. Under power and flow oscillating conditions, the two-phase flow behavior might be different from that under the steady conditions. Therefore, the thermal-hydraulic test using the rod bundle under oscillating conditions were performed to obtain the verification data for the analysis code. In this paper, the test results were described. It was found that the critical power decreased under flow oscillating conditions compared with under steady conditions, and the power oscillation had a little effect on the critical power.

著者

野崎 謙一朗 大川 富雄 堀田 亮年

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.75, no.751, pp.400-402, 2009-03-25

---

In the envisioned high-power density core plant, the degradation of stability is concerned that is attributed to the shortening of rod heat conduction time constant upon the dense fuel grid and the increment of pressure drop caused by the wall friction. To confirm the influence of such degradation on the fuel soundness, the bundle geometry critical power test was held under flow-power oscillation condition which envisages the unstable phenomenon occurring under in the flow transient event. This paper describes the analysis results of the cited test with sub-channel code NASCA, and the discussion of the mechanism of boiling transition under flow-power oscillating condition.

著者

服部 篤 岡田 昌志 Kang Chaedong

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.67, no.662, pp.2533-2540, 2001-10-25

参考文献数

8

被引用文献数

1

---

A water fine particle suspension with a uniform initial temperature and various initial concentration distributions in a rectangular vessel was heated from a vertical wall and cooled from the opposing vertical wall. The particle made of SiO_2 had a narrow size distribution (mean diameter of 2.96μm, standard deviation of 0.023μm). In order to observe phenomena of the natural convection, the temperature distribution, local particle concentration of the suspension and position of first interface were measured under various temperature differences between the opposing vertical walls. To make the influence of initial particle concentration on the phenomena clear, natural convection of suspension with three patterns of concentration, i.e. a naturally or artificially formed gradient, or non-gradient, was investigated. The pattern of formation of layers was classified by Grashof number. Moreover, to make the influence of initial depth of suspension clear, the suspensions with three initial depths, 50,100 or 160mm, were examined.

著者

稲葉 英男 森田 慎一

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.61, no.585, pp.1841-1848, 1995-05-25

被引用文献数

3

---

This work deals with physical properties of a fine capsulated latent heat storage material-water mixture. The fine capsulated material consists of pentadecane (C_<15>H_<32>, melting point of 283.1 K) as the core latent heat storage material and melamine resin as the coating material. The measured results of the physical properties of the test mixture, i. e. , density, latent heat and viscosity, were analyzed for the temperature region of solid and liquid phases of the core latent heat storage material (pentadecane). It was clarified that the additional properties law could be applied to the estimation of density and latent heat of the fine capsulated latent heat storage material. Moreover it was found that the viscosity of the test mixture increased with an increase in concentration of the fine capsulated latent heat storage material. Useful correlation equations of viscosity for the fine capsulated latent heat storage material-water mixture were derived in terms of temperature and concentration.顕熱に潜熱を上乗せすることによる多量の熱搬送が可能な微細潜熱蓄熱材を分散した混合水は、従来の低温水(顕熱)に代わる有効な熱搬送媒体の一つと考えられる水中に微細潜熱蓄熱体を分散混合する方法としては、エマルション化する方法および微細カプセル化混合する方法などが考えられる。エマルション化は、界面活性剤を用いた潜熱体の微細化そして安定分散化により均質混合水を容易に得ることが可能である。しかし、界面活性剤を用いるために高粘性の混合水となり、管内搬送時の圧力損失が大きくなる欠点を有する。固-液潜熱物質を微細カプセル化し、水と分散混合する方法は、均質な混合水をえるためにカプセル化潜熱物質を十分に微細化する必要がある。この微細カプセル化潜熱物質を分散した混合水は、連続相を水のみとすることができるために、圧力損失の増大を抑えることが可能である。この種の潜熱蓄熱材料は、水中にカプセル化された微細な潜熱体が分散している複雑な系を有することから、その物性の測定方法の検討などで困難な問題を伴い、その結果基礎データとしての物性値の評価が十分になされていない現状にある。本研究は、ペンタデカン(C15H32,凝固点Tfp=283.1K)を芯物質としメラミン樹脂をカプセル被覆とする微細カプセル化潜熱物質を水と混合した潜熱蓄熱材料の基礎データとしての密度、潜熱および粘性の測定結果を示すものである。微細なカプセル化潜熱物質混合水の密度および潜熱量の測定は、試料の温度制御が比較的安易な体積計法および示差走査熱量法により行われた。吉田は、直径100μm程度の多核カプセル化潜熱物質混合水の粘性測定を回転粘度計を用いて行い、非ニュートン挙動が示されることを明らかにすると共にべき乗則モデルによる近似を行っている。この種の混合水の粘性は、一般に非ニュートン挙動を示すことが知られている。本研究にいける粘性測定は、せん断速度を変化可能な回転粘度計を用いて行われた。物性値測定は、芯物質の固-液相変化を伴う温度範囲(T=273.1~298.1K)、そして微細カプセル化潜熱物質の質量割合Cca=10.2~40.8mass%の範囲において行われた。物性値測定の結果は、この種の潜熱蓄冷材料を用いた蓄冷システムの伝熱および流動特性予測に役立つ基礎資料を提供するものと思われる。

著者

竹内 正顕 鈴木 学 黒崎 晏夫 一色 尚次

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.443, pp.1493-1502, 1983-07-25

---

有風時の衣服の保温性低下に関する研究で,0.082m径の発熱円柱を使い4種の衣料(パンスト,タイツ,ラクダ,毛牝下)を実験した.接触層係数α*を考えた理論は,この実験の局所熱伝達率分布をよく表す.風が強くなると,身体に密着した薄いパンストやタイツが,むしろ毛靴下やラクダよりも保温性に優れる,理論的な計算結果はこのこともよく予想し得た.

著者

辻 裕 森川 敬信 上地 哲男 川崎 裕仁 関口 信樹

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.1901-1909, 1982-10-25

被引用文献数

2

---

ペデスタル成分とドップラ成分の両方に敷居値を設定することによって気流と粒子の信号分離が満足になされることを示した. この測定法を用いて気流および粒子の平均速度, 変動速度, 確立密度分布さらに気流乱れのスペクトルを求めた. その結果, 気流の乱れは粒子によって著しく減少すること, また粒子によって気流乱れの高周波成分は相対的に増加し, 低周波成分が減少することなどを明らかにした.

著者

吉川 英夫 渡辺 禎 池田 尊 三野 俊作

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.54, no.505, pp.2670-2674, 1988-09-25

---

In this study, a test of exhaust gas noise reduction is reported through the application of a heat-resistant epoxide resin, in place of a steel motorcycle muffler of a gas engine exhaust system. The findings show that this resin muffler results in a noise reduction without decreasing the engine efficiency, even in a restricted space. The experiments were conducted using the same shape for the steel and resin mufflers which were set at the outlet of a 250 ml engine exhaust system. The noise level of the exhaust gas after being introduced into the shielding compartment was measured by a standard noise-meter and FFT analyzer for the comparison of noise reduction effect.

著者

吉川 英夫 矢部 俊康 池田 尊 三野 俊作

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.54, no.505, pp.2675-2679, 1988-09-25

---

In this study, the exhaust gas noise reduction is reported through the application of a heat resistant epoxide resin, in place of a 1.5 L 4-cycle gas engine steel muffler. The findings show that this resin muffler of the same shape as a steel muffler results in noise reduction without decreasing the engine efficiency, even in a restricted space. Being measured by a standard noisemeter and FFT analyzer, the noise reduction effect was analyzed to have a relationship with the temperature of the muffler, and with the frequency.

著者

相原 利雄 嵯峨 隆一

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.49, no.447, pp.2410-2417, 1983-11-25

---

噴霧気流の優れた伝熱特性を利用して,フインを全く使用しない半導体冷却用放熱器の開発を志し,水噴霧と送風作用とを同時に営む噴霧気流発生装置を考案し,これと噴霧冷却面とを極めてコンパクトなユニットにまとめることに成功した.本報はその基磋研究の第一歩として,まず熱交換流路の一面が熱流束一様加熱で他面断熱の場合を取り上げ,送風量一定のもとで行った実験結果を記述したものである.

著者

飯田 明由 小久保 あゆみ 塚本 裕一 本田 拓 横山 博史 貴島 敬 加藤 千幸

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 (ISSN:03875016)

巻号頁・発行日

vol.73, no.732, pp.1637-1646, 2007-08-25

被引用文献数

6

---

The aim of this investigation is to understand the generation mechanism of aero-acoustic feedback noise radiated from rear-view mirrors. In order to clarify the relationship between the velocity fluctuation and radiated noise, correlation in terms of aerodynamic noise and velocity fluctuations were measured in a low-noise wind tunnel. The experimental results showed that noise level of the tonal-noise depended on the ratio of the height of the bump to the thickness of the boundary layer. Strong tonal-noise was generated when the height of the bump was almost equal to 40% of the height of the boundary layer. The tonal-noise level also depended on the length between the trailing-edge of the bump and the edge of rear-view mirror. The frequency of the tonal noise can be calculated by modified Rossiter equation. The tonal-noise was disappeared in the case of the bump was placed at separated boundary layer. It revealed that the seed of the tonal noise was small disturbances generated by the bump on the surface of the rear-view mirror.

著者

寺本 憲博 石崎 晋 吉田 義樹 辻本 良信 大橋 秀雄

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.61, no.591, pp.3854-3861, 1995-11-25

被引用文献数

5

---

A detailed study of the fluid moment on a precessing impeller shroud has been made. Experiments and calculations based on a bulk-flow model were carried out to elucidate the unsteady flow between the impeller shroud and the casing. The fluid moment was estimated from the pressure distribution on the impeller shroud in the precession motion. The results of the experiments were compared with those of the calculations. It was found that : (1) the moment largely depends on the leakage flow rate and the pressure loss at the impeller outer radius ; (2) a bulk-flow model incorporating the measured behavior of the pressure loss can simulate the complete leakage flow distribution fairly well ; (3) The fluid moment is mainly caused by the two-dimensional inviscid unsteady flow due to the precession motion.