著者

三宅 裕 稲葉 武彦 久保 尚重 竹岡 順一

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.50, no.460, pp.3211-3217, 1984-12-25

---

Externally pressurized supersonic gas thrust bearings whose generation of load capacity is substantially independent of the viscosity of working fluids, have been proposed and analyzed by the authors. This report presents the experimental results of the static characteristics of this new type of bearings. The experimental results including load capacity, stiffness, mass flow rate and pressure distributions in the bearing clearance, generally show a good agreement with the theoretical predictions and verify the validity of this new bearing. The effect of an orifice to improve the stiffness is also examined. Some problems which should be solved to put the bearing in practical use are pointed out.

著者

志賀 聖一 江原 秀治 柄沢 隆夫 倉林 俊雄

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.51, no.471, pp.3823-3827, 1985-11-25

---

In previous paper, it was suggested the effect of exhaust gas recirculation (EGR) on the diesel knock is relevant to the reaction rate of spontaneous ignition which occurs at the initial stage of diesel combustion. In a present study, this suggestion is verified by measuring the ignition lag and separating it into physical and chemical lags by applying the statistical technique presented by S. Kumagai. Under the operating condition used in this study, the physical lag is rather longer than the chemical lag and hardly changes with an increase in EGR ratio. On the other hand, the chemical lag is considerably affected by EGR. Though the dependent behaviour of the chemical lag on EGR is not simple, it is clearly shown that the tendency of chemical lag versus EGR ratio is quite the reverse of that of the diesel knock intensity. This means that the diesel knock intensity with EGR is dominated by the reaction rate of spontaneous ignition.

著者

吉川 大雄 菱沼 孝夫 近久 武美

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.652, pp.3218-3225, 2000-12-25

被引用文献数

17

---

The humidification system in a PEFC is handicapped by the water management under a range of temperatures including low temperatures in winter, so the performance with and without humidification was considered and simulated for a variety of fuel cell temperatures. The characteristice of a single cell with a cell area of 104 cm^2 was identified by experiments and a one dimensional model was developed to evaluate cell performance. The experiments found that water managements are important because the ionic conductivity of the membrane and catalyst layers decreases when there is little humidity. Results of start-up tests with the cell showed that the fuel cell recover the performance quickly in temperature as low as 10℃. The one dimensional simulation model showed that the measured cell performance agrees with the modeling results for various humidity conditions of the cell. If low reaction temperatures and low current densities are selected as operating conditions, it would be possible to apply the dry system at the start-up.

著者

松本 浩二 塩川 康夫 岡田 昌志 川越 哲男 カン・チェドン 平澤 良男

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.67, no.655, pp.804-809, 2001-03-25

被引用文献数

4

---

An ice storage is one of the ways of effective use of thermal energy. So, studies on a slush ice as thermal storage material have been done. We have also been studying on a suspension (slush ice) made of oil-water mixture with cooling and stirring. From our study result, it was found that a kind of additive having amino group (-NH_2) and silanol group (-SiOH) was essential to make the suspension with high IPF without adhesion of ice to a cooling wall. Moreover, formed ices in the suspension were dispersed and granular state and ices did not stick each other. In the present paper, we carried out experiments to clarify the characteristics of the suspension formation process. From the experimental results, it was found that the substance in the suspension was not ice but a compound consisting of ice and additive by a thermal analysis of fusion of the substance. Then, at very small depression of solidification point (about 7℃) all water of the mixture could be solidified by using the additive.

著者

能登 勝久 矢場田 真 中島 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.64, no.623, pp.2311-2318, 1998-07-25

被引用文献数

6

---

The cause and effect of fluid type on thermo-fluid pattern of the suppression of the isothermal Karman vortex street to a modified vortex street and a plume-like flow due to positive buoyancy in a circular cylinder wake with an upward freestream of mercury, air and water are made clear by solving numerically of the two-dimensional, laminar, time-dependent continuity equation, Navier-Stokes equations with the buoyancy term, and energy equation. For any type of fluid, the cause of the suppression is an extinction of wake vorticity ; shear layers increases and the wake vorticity decreases due to positive buoyancy. Behavior of the suppression is different each other in mercury, air and water, beacuse an increase of the wall vorticity and a decrease of the wake vorticity are different in those fluid.

著者

前田 太佳夫 鎌田 泰成 酒井 雄作 高原 直樹

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.71, no.701, pp.171-176, 2005-01-25

参考文献数

5

被引用文献数

5

---

This paper describes the measurement of the flow field around rotor blade. Three-bladed upwind rotor was tested in an open jet type wind tunnel. The rotor has a diameter of 2.4m. Flow field around rotor blade was measured with the use of two-dimensional LDV. The flow field was measured in x-y plane and z-y plane. The circulation around the blade sections were calculated by flow vectors around the rotor blade. The velocity vectors at optimum operation show a smooth flow around the blade and the bound vortex around blade cross-section seems to be persistent. On the other hand, the velocity vectors at stall condition demonstrate significant fluctuations in the near wake and separation on the blade suction side was observed. The circulation around blade span-wise section was calculated at the certain control volume. By the observation of flow field and calculated results of circulation, it seems that the flow is separated at the blade from middle-span region to tip region at stall condition. No separation was observed at the blade root region.

著者

岡村 隆成 古閑 昭紀 川岸 裕之

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.66, no.646, pp.1436-1443, 2000-06-25

---

The heat transfer characteristics and flow behavior in a rectangular passage with two opposite 45゜skewed ribs for turbine rotor blade have been investigated for Reynolds numbers from 7800 to 19000. In this blade, the spanwise coolant passage at the trailing edge region whose thickness is very thin is chosen, so the channel aspect ratio(=width/height of channel)is extremely high, 4.76. Therefore the heat transfer experiment in the high aspect ratio cooling channel was performed using thermochromic liquid crystal and thermocouples. Furthermore the calculation of flow and heat transfer was carried out using CFD analysis code to understand the heat transfer experimental results. The enhanced heat transfer coefficients on the smooth side wall at rib leading end were the same level as those on the rib roughened walls.

著者

坂本 健太郎 遠藤 小太郎 行本 正雄 武田 邦彦

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 = Transactions of the Japan Society of Mechanical Engineers. B (ISSN:03875016)

巻号頁・発行日

vol.72, no.722, pp.2338-2345, 2006-10-25

参考文献数

24

---

The amount of woody biomass resources in Aichi Prefecture and Toyone Village was estimated on the basis of theoretical and actual production efficiencies. Five factors should be considered at the steady production of reduced carbon from carbon dioxide by sunlight in woods. The ratio of leaf to forest area, the reflection of sunlight on leaf surface, the conversion efficiency from the light energy, efficiency of optical system, and of dark reaction are 0.70, 0.82, 0.24, 0.31, and 0.92 respectively. On the other hand, four factors are in the timber production stage. The energy consumption loss for the daily life of woods, the waste at the forest, the thinner woods to main cutting production, and the thinning are 0.50, 0.47, 0.435, 0.44, respectively. The total efficiency was calculated and the result was 0.0023. Furthermore, near fiscal year 2000, primary energy consumption in Aichi Prefecture is 1.48×10^9 GJ/year, so it is 2200 times than the present production amount and 300 times the best theoretical production amount.

著者

谷下 一夫 棚沢 一郎 山口 隆美 菅原 基晃

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.456, pp.1945-1954, 1984-08-04

被引用文献数

1

---

血液における炭酸ガス拡散係数は,人工肺のガス交換性能を評価するために必要であるが,実測値が全くない.そこで,静止血液試料層を用い,準定常法により炭酸ガスの有効拡散係数を測定した.温度の下降および赤血球濃度,血しょう(漿)たん白濃度の増加とともに,拡散係数が低下する結果を得た.さらに,赤血球内の炭酸脱水酵素の効果により,溶血した血液およびヘモグロビン溶液において顕著な促進拡散が認められた.