著者

石綿 良三

出版者

一般社団法人 日本機械学会

雑誌

年次大会講演論文集 2008.5 (ISSN:24331325)

巻号頁・発行日

pp.457-458, 2008-08-02 (Released:2017-08-01)

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The phenomena with relation to fluid mechanics are often taken up in books on science for popular readers. However, the explanation on principle of them has been described under misunderstood knowledge on fluid mechanics in many books. It seems the reason that the many authors are not understood fluid mechanics enough. Also, there is the further reason in the descriptions involved mistaken explanations in many books. In present study the mechanism of transmission of so misunderstood explanations has been considered, and the diffusion of them has been investigated. It is also examined and proposed how to prevent the transmission and diffusion.

著者

前田 正登

出版者

一般社団法人 日本機械学会

雑誌

シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集

巻号頁・発行日

vol.2016, pp.B-11, 2016

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<p>In this study, throwing experiments were conducted with the participation of six javelin throwers using a wooden javelin produced to conform to the current regulations for javelin throw competitions and a normal javelin made by duralumin. In the experiments, the wooden javelin and duralumin javelin were thrown and the following release parameters were measured: initial velocity, release height, release angle, attitude angle, and angle of attack). The distances of the throws were measured and the effects of the release parameters were assessed. As a result, it was found that the thrown distance of the wooden javelin was slightly shorter than that of the duralumin javelin, but the difference was not significant. Similarly, no significant difference was observed in each release parameter. The standard deviation of each release parameter was relatively large, and individual differences between the throwers were considered to be one of the causes.</p>

著者

土井 幸輝 小田原 利江 林 美恵子 藤本 浩志

出版者

一般社団法人 日本機械学会

雑誌

福祉工学シンポ

巻号頁・発行日

vol.2003, pp.201-204, 2003

被引用文献数

2

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点字は, 視覚障害者にとって自らが読み書き出来る唯一の文字として一般に知られているが, 近年, スクリーン印刷による紫外線硬化樹脂インク点字(以下UV点字と記す)サインが, 共用品として急激に普及している。しかし, 製作者ごとにUV点字パターン(点間隔・高さなど)が大きく異なるため, 触読しにくいことが指摘されている。そのため, 現在, UV点字に関する日本工業規格化が検討されている。そこで, 本研究では, 触読しやすいUV点字パターンを明らかにすることを目的とし, ヒトの指先の皮膚感覚レベルで, 点字の点間隔・高さの違いがどの程度識別容易性に影響を与えるのかを調べた。実験には, 点字触読における経験要素を排除するため, 晴眼者に参加してもらい, さまざまな点間隔・高さの6文字(1点欠け)について, 同定課題を行った。これより, 識別しやすいUV点字パターンの有用な基礎データが得られた。

著者

松島 和男 廣瀬 敏也 関根 道昭 谷口 哲夫

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C編 (ISSN:03875016)

巻号頁・発行日

vol.75, no.751, pp.535-537, 2009

参考文献数

1

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It is mandatory to apply a pressure relief device (PRD) on the Fuel cell vehicles to avoid explosion of high pressure hydrogen gas container when a vehicle explore to be on fire. Several hydrogen release tests were carried out to understand how the released hydrogen behaves in a vehicle fire. These tests are to analyze the release way of PRD as below. 1) The range of flame, flame temperature and the time of release when PRD effused hydrogen gas in upward direction, in downward direction, and in horizontal direction respectively. 2) The diffusion way of released hydrogen gas. 3) The effect of diffusion box which was assumed to decrease the hydrogen concentration and flow rate. The results showed that it should be avoided to release directly hydrogen gas into the air in the horizontal direction

著者

前田 耕造 吉村 弘 奥村 由和 安藤 知佳子

出版者

一般社団法人 日本機械学会

雑誌

環境工学総合シンポ

巻号頁・発行日

vol.2001, pp.25-30, 2001

著者

灘野 宏正 中迫 正一 河野 正来 南 一郎 山口 博幸

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.70, no.690, pp.554-559, 2004-02-25 (Released:2011-03-04)

参考文献数

7

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To clarify the wear resistance and seizure resistance of the vegetable oils with anti-wear additives of Dibenzyl-Disulfide (DBDS) and Phosphonic Acid-Dibutyl (DBPo), the four-ball tests were carried out under dip-feed lubrication using Soda-type four-ball machine. The width of the wear scar on the stationary balls lubricated with the vegetable oils containing DBPo additive was smaller than that without the additive, and was smaller than that containing DBDS additive. The seizure resistance of the vegetable oils with DBDS additive increased in following order : Turbine oil<Rapeseed oil<Soybean oil<Corn oil. On the other hand, the seizure resistance of the vegetable oils with DBPo additive increased in the following order : Turbine oil<Soybean oil<Corn oil<Rapeseed oil. The DBPo additive showed significant improvements in seizure resistance compared with DBDS additive.

著者

灘野 宏正 中迫 正一 河野 正来 南 一郎 山口 博幸

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.70, no.690, pp.554-559, 2004

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To clarify the wear resistance and seizure resistance of the vegetable oils with anti-wear additives of Dibenzyl-Disulfide (DBDS) and Phosphonic Acid-Dibutyl (DBPo), the four-ball tests were carried out under dip-feed lubrication using Soda-type four-ball machine. The width of the wear scar on the stationary balls lubricated with the vegetable oils containing DBPo additive was smaller than that without the additive, and was smaller than that containing DBDS additive. The seizure resistance of the vegetable oils with DBDS additive increased in following order : Turbine oil<Rapeseed oil<Soybean oil<Corn oil. On the other hand, the seizure resistance of the vegetable oils with DBPo additive increased in the following order : Turbine oil<Soybean oil<Corn oil<Rapeseed oil. The DBPo additive showed significant improvements in seizure resistance compared with DBDS additive.

著者

高橋 勉 坂本 夏澄 Withun HEMSUWAN 吉武 裕美子

出版者

一般社団法人 日本機械学会

雑誌

流体工学部門講演会講演論文集 2016 (ISSN:24242896)

巻号頁・発行日

pp.0617, 2016 (Released:2017-06-19)

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A newly developed innovative wind / water turbine mechanism that is driven by longitudinal vortex is introduced. The blades of a conventional propeller type windmill with a horizontal rotation axis are replaced to the simple circular cylinders and a ring shaped plate is placed in the wake region. Once the propeller starts to rotate a certain direction, the longitudinal vortex appears stably behind the cylinder and the steady lift force is generated. It can rotate to the CW or CCW direction and the rotation direction is decided by the initial rotation direction. This new turbine is the simple structure, toughness and high torque feature. Therefore, it has a great possibility to use as a wind turbine to generate electricity even in the high speed wind without the pitch controller. It can apply for wider purposes, such as a turbine with high corrosion resistance and temperature resistance. We can also manufacture a micro-size turbine easier.

著者

木原 玄悟 吉本 勇太 堀 琢磨 高木 周 杵淵 郁也

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.84, no.865, pp.18-00193, 2018 (Released:2018-09-25)

参考文献数

33

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We constructed a coarse-grained (CG) water model based on non-Markovian dissipative particle dynamics (NMDPD) taking into account memory effects. The NMDPD equation of motion was derived from a generalized Langevin equation formulated via the Mori–Zwanzig (MZ) projection operator. We extracted a CG pair potential and memory kernels between clusters comprising 10 water molecules by means of molecular dynamics (MD) simulations. We found that the MZ-guided CG potential followed by an iterative Boltzmann inversion correction resulted in an accurate representation of both a radial distribution function and pressure. Furthermore, in contrast to Markovian DPD, the NMDPD model exploiting MZ-guided memory kernels could reproduce short-time dynamics originating from molecular collisions, which was characterized by decaying nature of a velocity autocorrelation function (VACF). The NMDPD model was also able to reasonably represent the viscosity of the MD system compared to the conventional DPD, where interaction parameters were phenomenologically tuned such that a few macroscopic properties were reproduced, leading to a significant underestimation of a viscosity or Schmidt number. Finally, the differences of the viscosity and long-time behavior of the VACF between MD and NMDPD systems implied the necessity of a more appropriate description for a one-to-one correspondence between a CG particle and a water cluster.

著者

宮﨑 達二郎 井上 卓真 野田 尚昭 佐野 義一

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

巻号頁・発行日

vol.84, no.864, pp.18-00013-18-00013, 2018

被引用文献数

2

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<p>In this paper, convenient analysis methods are proposed for analyzing the singular index and the intensity of singular stress field (ISSF) at the vertex on the interface in the three dimensional (3D) bonded body. The analysis methods focus on FEM stresses at and around the vertex. The singular index is determined from the FEM stress ratio at the vertex obtained by performing FEM analyses for the finely and coarsely meshed models. Then, the ISSF is determined from the average FEM stresses around the vertex obtained for the reference and unknown models by applying the similar mesh pattern. The validity of the present methods is examined by comparing the results of 3D bonded models with/without fixed free surfaces. It is found that the obtained singular index has the same accuracy as the FEM eigenvalue analysis. The asymptotic solutions with the singular index and ISSF obtained by the present method correspond to FEM stress distributions. Since the ISSF obtained by the body force method (BFM) is used as the reference solution, the present method for ISSF has the same accuracy as BFM. Moreover, the critical ISSF values are calculated from the experimental results of the butt joints under various adhesive thicknesses. The critical ISSF at the side of 3D butt joint is in good agreement with the critical ISSF of 2D butt joint model. It is shown that the critical ISSF at the vertex of 3D joint is constant as well as the critical 2D ISSF independent of the adhesive thickness.</p>

著者

宮﨑 達二郎 井上 卓真 野田 尚昭 佐野 義一

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

巻号頁・発行日

2018

被引用文献数

2

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<p>In this paper, convenient analysis methods are proposed for analyzing the singular index and the intensity of singular stress field (ISSF) at the vertex on the interface in the three dimensional (3D) bonded body. The analysis methods focus on FEM stresses at and around the vertex. The singular index is determined from the FEM stress ratio at the vertex obtained by performing FEM analyses for the finely and coarsely meshed models. Then, the ISSF is determined from the average FEM stresses around the vertex obtained for the reference and unknown models by applying the similar mesh pattern. The validity of the present methods is examined by comparing the results of 3D bonded models with/without fixed free surfaces. It is found that the obtained singular index has the same accuracy as the FEM eigenvalue analysis. The asymptotic solutions with the singular index and ISSF obtained by the present method correspond to FEM stress distributions. Since the ISSF obtained by the body force method (BFM) is used as the reference solution, the present method for ISSF has the same accuracy as BFM. Moreover, the critical ISSF values are calculated from the experimental results of the butt joints under various adhesive thicknesses. The critical ISSF at the side of 3D butt joint is in good agreement with the critical ISSF of 2D butt joint model. It is shown that the critical ISSF at the vertex of 3D joint is constant as well as the critical 2D ISSF independent of the adhesive thickness.</p>

著者

森島 圭祐 水内 淳 阿部 光一郎 古木 翔 山中 仁寛 大本 浩司

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C編 (ISSN:18848354)

巻号頁・発行日

vol.79, no.806, pp.3561-3573, 2013 (Released:2013-10-25)

参考文献数

31

被引用文献数

1 2

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In this study, we conducted an experiment aimed at developing an effective method for measuring the useful field of view when driving while maintaining free visual (eye and head free) conditions with completely unobstructed head and eye movements. In the experiment, the mental workload was changed in a stepwise manner in order to test the hypothesis that the useful field of view becomes narrower as the mental workload (MWL) increases, as well as to verify the accuracy of the proposed method. The results confirmed the validity and accuracy of the proposed method for measuring the useful field of view under completely unobstructed visual conditions.

著者

佐味 弘之 高野 孝義 谷沢 清岳 吉富 和宣 伊東 聰智 宮崎 敏

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.69, no.678, pp.512-520, 2003-02-25 (Released:2008-03-28)

参考文献数

14

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The ignition phenomena of diesel fuel spray injected into a constant volume vessel with medium injection pressure were investigated. Results show that ignition occurs at a certain point near the surface of spray liquid column before breakup where activation reaction is advanced one step ahead of others and the impingement plate assists surface ignition. From these results was deduced the following concept that fuel vaporized from the liquid surface begins to be activated when the velocity gradient at the liquid column surface decreases to a certain level, leading to ignition. The blowing-off limited ignition model was proposed from this concept. Based on the functional relation between various factors and the ignition delay derived from this model, the ignition delay date were well arranged into an experimental formula. Next, ignition investigation was carried out using a bottom-viewed single cylinder engine, revealing that the effects of many factors including EGR rate related to O2 concentration can be analyzed comprehensively based on the above model.

著者

藤井 正浩 國冨 裕太 石田 浩規

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.80, no.820, pp.TRANS0339, 2014 (Released:2014-12-25)

参考文献数

8

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In order to clarify the effect of surface profile on friction characteristics of viscoelastic material used for oil seal, sliding test was conducted under oil lubrication with the NBR (Nitrile Butadiene Rubber) specimen in combination with steel specimen. The sliding surface profiles with different feature in the steel specimens were introduced by polish process and blast process. The NBR specimens with different surface feature were also employed. Under a low load condition, steel specimens with plateau surface showed the lower friction coefficient. The reduction of contact area and pocket effect could lead to the lower friction coefficient. Similar effect was provided by the NBR specimens with rough surface or dimples. Friction behavior under a low load condition was influenced by adhesion force. The adhesion force decreased with increasing surface roughness, that is with decreasing contact area. Therefore, the friction coefficient decreased with increasing surface roughness in NBR specimen. The friction coefficient of the NBR specimen with dimples which had small asperity and large concave portion was remarkably small under a low load condition. On the other hand, under a high load condition, where the deformation of NBR specimen was rather large, the effect of surface profile on friction coefficient was small.

著者

橋本 博文 今井 栄一 矢野 創 渡辺 英幸 横堀 伸一 山岸 明彦

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

巻号頁・発行日

vol.82, no.835, pp.15-00538-15-00538, 2016

被引用文献数

1

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The mechanical thermometer using a bimetallic strip coil was developed for the Tanpopo mission. The Tanpopo mission is a multi-year passive exposure experiment for astrobiology exposure and micrometeoroid capture onboard the Exposed Experiment Handrail Attachment Mechanism (ExHAM) at the Japanese Experiment Module 'Kibo' (JEM) Exposed Facility (EF) on the International Space Station (ISS). The Tanpopo mission apparatuses were launched by the SpaceX-6 Dragon CRS-6 on April 14 2015, from the Cape Canaveral Air Force Station in the U.S.A. Since its microbial exposure experiment requires recording the maximum temperature that the Tanpopo exposure panel experiences, we have developed a mechanical thermometer with no electric power supplied from the ExHAM. At a given time and orbital position of the ISS, the thermometer indicator was video-imaged by the extravehicular video camera attached to the Kibo-EF and controlled from the ground. With these images analyzed, we were able to derive the maximum temperature of the Tanpopo exposure panels on the space pointing face of the ExHAM as 23.9±5 °C. Now this passive and mechanical thermometer is available to other space missions with no electric supplies required and thus highly expands the possibility of new extravehicular experiments and explorations for both human and robotic missions.

著者

村瀬 守正 鋤柄 直 玉山 千雅 奥村 毅 安井 誠 川嶋 紘一郎

出版者

一般社団法人 日本機械学会

雑誌

材料力学部門講演会講演論文集

巻号頁・発行日

vol.2004, pp.93-94, 2004

著者

佐藤 航 磯島 宣之

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.82, no.844, pp.16-00207, 2016 (Released:2016-12-25)

参考文献数

21

被引用文献数

2

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To achieve precise temperature control, Peltier devices, which are also called thermoelectric coolers, are widely used. However, simulating the unsteady temperature history caused by the Peltier devices is difficult because the amounts of heat absorption and generation are affected by their temperature. The temperature dependence reportedly can be calculated using the quadratic equation of temperature and the typical temperature characteristic coefficients. However, as the temperature dependence varied among the manufacturers, the temperature characteristic coefficients had to be modified for each of the devices. We developed a technique to determine the temperature characteristic coefficients of the Peltier device automatically by using data assimilation. We integrated the particle filter, one of the data assimilation algorithms, into the thermal network method and enabled estimating the suitable temperature characteristic coefficients. To demonstrate the estimation, we evaluated a Peltier device. The constant current 1.0 A and its inverse current were applied to the sample device repeatedly, and the temperature of the control object fluctuated repeatedly between 40 °C and 90 °C was measured. The temperature change was simulated using the thermal network method with the typical temperature characteristic coefficients and the history was compared with the measurement results. The root mean square error of temperature between the measurement and the calculation results was 3.20 K. Then, we estimated the applicable value of the temperature characteristic coefficients by applying the particle filter combined with the thermal network model. When the estimated coefficients were applied to the thermal network model, the root mean square error of temperature decreased to 1.39 K.

著者

格内 敏 厳 希哲 坂本 亨 村上 惇 池田 大作 藤原 紘郎

出版者

一般社団法人 日本機械学会

雑誌

関西支部講演会講演論文集 2000.75 (ISSN:24242756)

巻号頁・発行日

pp._11-53_-_11-54_, 2000-03-16 (Released:2017-06-19)

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Various implants are employed to provide osteosynthesis of the trochanteric fracture of femur by providing mechanical fixation. However, pain due to the stress concentration in the bone and new fracture are caused, when the implant does not physically suit the patient. The purpose of this study is to compare the mechanical properties between fixation implant devices of differing design by holographic interferometry.

著者

鈴木 正己 荒川 忠一

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.604, pp.4135-4141, 1996-12-25 (Released:2008-03-28)

参考文献数

9

被引用文献数

1

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The numerical methods for analyzing a fixed terminator type of wave energy conversion device are described under the condition that the linear water wave theory is applicable. Two methods are proposed in order to calculate the device characteristics of an air chamber. One uses the flow rate and the gage pressure in the air chamber directly, because the interaction between the oscillating water column and the turbine is found to be controlled only by the flow rate and the pressure drop through the turbine in this system. The other method uses the equation of the floating body motion in a manner similar to the equivalent floating body approximation. The relations between these two methods are also examined. The hydrodynamic performance with frequency from zero to infinity is required in the simulation of irregular waves. However, resonances occur when the air chamber breadth is equal to an integral multiple of a half wavelength. Therefore the impulse response function is modified in order to eliminate the effects of the resonance frequency. Finally, it is confirmed that these solutions give good agreement with the experimental data.

著者

森脇 一郎 上田 昭夫 射場 大輔

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.84, no.863, pp.18-00033, 2018 (Released:2018-07-25)

参考文献数

9

被引用文献数

1

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The present paper describes edge contact analyses for power transmission gears using tooth-flank-film elements, which have been proposed for finite element analyses of tooth stresses. For edge contact analyses, the tooth-flank-film elements are placed not only on usable flanks but also over tooth edges. Finer elements on edge neighboring areas and on the parts of usable tooth flanks where tend to contact with mating edges enable the edge contact to be analyzed. Comparisons of calculated distributions of tooth contact stress with observed tooth flanks after a running test showed the validity of the proposed method for edge contact analyses.