著者
丸茂 喜高 清水 勇介 竹内 亮佑 綱島 均 小島 崇
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.817, pp.TL0280-TL0280, 2014 (Released:2014-09-25)
参考文献数
9

This study proposes a driving assistance system to inform the notch operation timing for train drivers. The assistance system indicates visually the notch-off position where the driver releases the accelerator. The notch-off position is calculated by the present vehicle acceleration, velocity and position by assuming the constant acceleration. The assistance system also indicates the brake onset and the predicted stopping positions. Two experiments are conducted by using the train-driving simulator. One experiment examines the effects of the notch-off and brake onset timing on the vehicle velocity and the running time. The assistance system makes it possible to adjust the vehicle velocity and the running time. The other experiment examines the three running patterns by combination of the notch-off and the brake onset positions. With the time recovering pattern, which is combination of the higher notch-off velocity and the later brake onset timing, the assistance system realizes the shorter running time in comparison with the standard running pattern. With the energy saving pattern, which is combination of the lower notch-off velocity and the later brake onset timing, the assistance system prevents the time delay by the later brake timing even if the velocity is lower than the standard running pattern.
著者
品川 晃徳 野澤 久幸 内山 裕太郎
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.83, no.854, pp.17-00086-17-00086, 2017 (Released:2017-10-25)
参考文献数
4

It is thought that the first step to understanding vehicle movement is to measure and analyze that movement in order to confirm that it falls within the range of the laws of physics. In the case of a four-wheeled vehicle, in general, the friction limit is defined within the circle of longitudinal acceleration and lateral acceleration through the use of a G-G diagram. Then measurements are taken to confirm that the driving state is within that range. Two-wheeled off-road vehicles are mainly ridden on slippery dirt roads that include steep slopes and rough, uneven surfaces. An analysis method for the driving state and the vehicle movement limits that would be suitable for analyzing the movement of such two-wheeled off-road vehicles under these conditions was examined. These movement limits were then formulated by taking into consideration the coefficient of friction and the road surface gradient in accordance with the basic laws of physics and also by focusing on the vehicle movement in the longitudinal direction. Measurements were also taken during actual off-road riding by top-class Japanese off-road motorcycle riders. It was confirmed that this measurement data was distributed within the range of the assumed vehicle movement limits. Consequently, it was confirmed that it is possible to use such measurements to accurately grasp the vehicle movement limits and the associated driving state for two-wheeled off-road vehicles.
著者
松本 光広
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.834, pp.15-00127, 2016 (Released:2016-02-25)
参考文献数
16

A bicycle wheel consists of a hub, spokes, nipples and a rim. The rim deforms from true circle to irregular circle when a worker assembles the wheel. People can ride a bicycle in safety when the rim is the true circle. The worker needs to correct the deformed rim. The worker can correct the deformed rim through the use of a relation between a nipple position to rotate a nipple rotation angle and rim displacements. I developed a task support equipment to correct the deformed rim through the use of the relation. The worker does not need to know the relation through the use of the developed task support equipment. The worker can correct the deformed rim through the use of the developed task support equipment. The developed task support equipment shows the worker the nipple position to rotate the nipple rotation angle. The worker rotates the nipple as shown by the developed task support equipment. I measured the relation between the nipple rotation angle and the rim displacements. I suggested a method to calculate the corrected rim displacements through the use of the relation. I made up a hardware and a software in the task support equipment. I implemented the method in the software. I checked performance of the developed task support equipment. I corrected the deformed rim through the use of the developed task support equipment. The results have shown the usefulness in the developed task support equipment for correcting the deformed rim.
著者
奥野 航平 松尾 亜紀子
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.83, no.856, pp.17-00369-17-00369, 2017 (Released:2017-12-25)
参考文献数
20

The numerical analysis on the flight stability of the underwater projectiles are performed using computational fluid dynamics code which consists of gas/liquid phases analysis, 2D calculation method. The nose shape effect on the underwater flight stability is conducted. The ogival nose, the flat nose and the spike nose are used for the nose shapes. The static stability is determined by the direction of pressure on the projectile. The pressure on the flat nose makes projectile stable, although pressure on the ogival nose and the horizontal area of flat nose makes projectile unstable. The spike nose is statically unstable, however it is possible to increase the flight stability by changing the spike radius and the spike length. When the part of projectile gets out of the bubble and contacts with water, the water pressure acts as restoring force, which lead to improve the flight stability. This phenomenon is called ‘Tail slapping effect’. Tail slapping effect works most effectively when only backward of the center of gravity of the projectile contacts with water. The Effects is canceled as the angle of attack increases and the front of the projectile contacts with water. As a result, the improvement of stability due to the tail slapping effect is limited.
著者
岸 祐希 金崎 雅博 牧野 好和 松島 紀佐
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.83, no.849, pp.16-00454-16-00454, 2017 (Released:2017-05-25)
参考文献数
20

When a wing of airplane is designed, it is necessary to have knowledge regarding planforms considered their optimum airfoils in order to design efficiently, because each wing planform has both of advantage and disadvantage. In this study, the wing design problem for supersonic transport is carried out for different planforms for two different planforms. Multi-objective problem, which is minimization drags for two supersonic cruise conditions (transonic and supersonic flight) is solved to obtain knowledge of the supersonic airfoil from the viewpoint of the multi-point design. Two types of planforms are considered—a cranked arrow wing with a high sweep-back angle and a single tapered wing with a low sweep-back angle. Optimization problems are carried out by efficient global optimization, which is evolutionary algorithm based on the Kriging surrogate model. To acquire design knowledge, a parallel coordinate plot and functional analysis of variance (functional ANOVA) are applied. The design results showed the difference airfoil between two planforms. The optimum airfoil for the single tapered wing has a small or negative camber at the leading edge to minimize the supersonic cruising. On the other hand, the optimum airfoil for the cranked arrow wing has an airfoil with a lower thickness and larger camber at the leading edge.
著者
熊谷 正芳 石渡 正人 大谷 眞一
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 (ISSN:21879761)
巻号頁・発行日
vol.84, no.863, pp.18-00139, 2018 (Released:2018-07-25)
参考文献数
18

Residual stress measurements on pipe-shaped Ni-alloy, Inconel 625, were conducted. The pipes were made from a thin plate by roll-bend and weld along longitudinal direction of the pipe. Shot peening processes were performed to the outside surface of the pipes. The stresses were measured using X-ray stress measurement method. The residual stresses on the specimen before shot peening process were around 100 MPa toward longitudinal direction and around 250 MPa toward transvers direction to the welding direction. The residual stresses changed to 800 MPa in compressive by shot peening process. After thermal aging at 1173 K for 1 and 10 hour, the residual stresses changed to −100 MPa on the specimens with and without shot peening in both longitudinal and transvers directions. In addition, optical microscopic observation and the analyses of X-ray diffraction peaks were performed to reveal microstructural features due to welding, shot peening, and thermal aging. Equiaxed and columnar dendrites were generated in the center and the outer of fusion zone, respectively. The grains in the heat affected zone, between the fusion zone and base metal became larger. The grains near the surface even in welds became small by shot peening processes according to analyses of X-ray diffraction peaks. Even though induced compressive residual stresses were released during thermal ageing, refined grains had been smaller than before shot peening process.
著者
川那辺 洋 石山 拓二 塩路 昌宏
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.83, no.856, pp.17-00294-17-00294, 2017 (Released:2017-12-25)
参考文献数
5

Entrainment process of surrounding fluid for a diesel spray is investigated based on the momentum theory and 1-D simple spray model developed by Musculus et. al. Entrained fluid distribution along the spray axis is theoretically estimated. The results show that the absolute value of entrainment velocity depends on axis location and is inversely proportional to the distance from the nozzle. Therefore, the large amount of entrained fluid comes from the upstream region near field of nozzle. 1-D simple spray model is performed for the same target and the effect of the injection rate on entraining process is clarified.
著者
山本 勝太 牧野 一成 石塚 弘道
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.83, no.856, pp.17-00337-17-00337, 2017 (Released:2017-12-25)
参考文献数
10

The integrity of railway axles is a critical aspect for ensuring the safety of a railway system. Therefore, non-destructive inspections such as ultrasonic testing and magnetic particle testing are conducted periodically. Some railway operators conduct ultrasonic tests directly on axles mounted on the train. However, the axles have to be disassembled for conducting magnetic particle testing. In the present study, the effects of variable amplitude stress acting on cracks and axle bending stress during ultrasonic test on ultrasonic response are discussed. An ultrasonic test was conducted using a full-scale axle specimen that had fatigue cracks and no artificial notches. The ultrasonic response was evaluated for the cracks whose lengths were 10 mm, 16 mm, and 19 mm. Under an unloaded condition, the ultrasonic response for the 16-mm-long and 19-mm-long cracks was approximately 4 or 7 times higher than that for the 10-mm-long crack, although the cross-sectional area of each of these cracks was approximately 2.5 or 3.5 times larger than that of the 10-mm-long crack. The obtained results indicate that the contribution of the reflection area to the ultrasonic response under a variable amplitude stress differs from that under a constant stress condition. Moreover, the influence of axle bending stress ranging between -50 MPa to +47 MPa on the ultrasonic response was investigated. A higher bending stress led to a higher ultrasonic response. However, the decreasing rate of ultrasonic response caused under compressive stress was lower than the increasing rate under tensile stress. For example, the ultrasonic response was approximately 2 dB lower than that under the unloaded condition at a compressive stress of -30 MPa; however, the ultrasonic response showed an increment of approximately 4 dB at a tensile stress of 30 MPa. A similar trend was observed in the crack of each length. The results denote that the crack position influences the precision of crack detection in ultrasonic inspection. However, considering that the maximum static bending stress of axles used in Japan is 30 MPa, its effect on inservice axle inspection is negligible.
著者
中川 健一 長谷川 裕晃 村上 正秀 大林 茂
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.83, no.856, pp.17-00165-17-00165, 2017 (Released:2017-12-25)
参考文献数
13

Badminton is one of the most popular sports in the world and is famous as the sport having the fastest initial velocity of a batted ball among all ball games. Initial velocity immediately after smashing may reach up to 408 km/h (113 m/s) at maximum. A badminton shuttlecock generates significant aerodynamic drag and it was confirmed that the high deceleration characteristics was related to the slots located at the leg portion of a shuttlecock in the previous study. Turnover refers to the flipping experienced by a shuttlecock when undergoing heading change from nose pointing against the flight path at the moment of impact and a shuttlecock indicates the aerodynamically stable feature for the flip movement just after impact. The purpose of this study is to investigate the effect of gaps on the aerodynamic stability (turnover stability) of a badminton shuttlecock during the flip phenomenon. In the present study, the flow field around the shuttlecock during impulsive change of an angle of attack (flip movement) was measured by using the smoke flow visualization and the behavior of the shuttlecock during the flip movement was evaluated in comparison with that of the conic model (with no gaps). The turnover stability of a badminton shuttlecock is affected by gaps of the shuttlecock skirt.
著者
鈴木 明宏 茂庭 優貴 石井 賢治 藤原 誠助 永富 良一
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 (ISSN:21879761)
巻号頁・発行日
vol.83, no.849, pp.16-00450-16-00450, 2017 (Released:2017-05-25)
参考文献数
10

Amount of daily physical activity is strongly associated with the prevalence of lifestyle-associated diseases, and thus maintaining a certain level of physical activity is recommended. Amount of physical activity, namely energy expenditure, is commonly estimated from linear regression analysis of oxygen uptake during steady-state exercise of different intensities. Short-duration exercise, mainly walking lasting less than 3 minutes, has been reported to account for over 90% of the daily energy expenditure of healthy adults. The estimation of energy expenditure by ACSM Metabolic Equations used well, however, is based on steady-state exercise of more than 5 minutes, and energy consumption of shorter duration exercise is not commonly considered. Oxygen consumption remains elevated for some period of time after exercise. Then, the estimation of energy expenditure for short duration exercise must include excess post-exercise oxygen consumption (EPOC). The amount of EPOC change in duration exercise. Therefore, we attempted to elucidate the energy expenditure for VO2 kinetics. Ten healthy participants aged 19-54 y walked and ran for 1, 3 and 5 minutes on a treadmill at constant speed. Oxygen consumption during and post-exercise was measured using a portable gas analyzer in breath-by-breath mode. A best-fit exponential equation to estimate oxygen consumption from exercise duration and walking speed was generated. The root mean square (RMS) of estimate equations was calculated using Leave-one-out cross validation. The RMS(1.44~2.14 ml/kg/min) was lower, and the results of the Bland-Altman analysis revealed neither fixed nor proportional bias with the exception of the decent walking and running. An equation for the estimation of oxygen consumption at shorter durations of exercise was successfully generated. Accumulation of additional data may further improve the equation.
著者
近藤 千尋 佐野 広季 山根 浩二 小坂田 潔 河崎 澄
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.83, no.847, pp.16-00375-16-00375, 2017 (Released:2017-03-25)
参考文献数
11

This paper describes how to produce a biodiesel from the oil in the waste soup of ramen noodles, and especially clarifies an amount of oil in waste soup, the energy profit ratio (EPR) of the production of biodiesel from the oil in waste soup of ramen noodles and the engine performance of the biodiesel from waste soup of ramen noodles. As a result, from the waste pig bone (ton-kotsu) soup the recovered tri-glyceride was about 11g per a soup. The biodiesel produced from the oil in the waste soup of ramen noodles by using ordinary alkyl catalyst method has low cold flow properties, due to the high content of the saturated fatty acid methyl ester such as C16:0, C18:0 and so on. And it is estimated that the amount of BDF from a ramen noodle restaurant is about 2.4L if the customers are around 300 per day, and this means that the 9.9 kW co-generation system is able to be operated for an hour per day. About energy profit ratio analysis, if the oil separation process is improved, EPR from the waste soup to biodiesel will become higher than 5.0. Furthermore, engine test is performed by using BDF from the waste soup of ramen noodles as B5. As a result, it is shown that fuel consumption rate and emissions are almost the same as the case of using gasoil.
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 (ISSN:21879761)
巻号頁・発行日
2016

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
松本 浩乃 窪田 佳寛 大石 正行 望月 修
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.833, pp.15-00389-15-00389, 2016 (Released:2016-01-25)
参考文献数
13

The typhoon often causes a serious damage of the apple before harvest. Many apples fall from trees by the strong wind. These apples are bagged to protect them from insects and control sun light for the apples coloring while they are ripening on the tree. We conceive that the wind-force acting on the bagging apple exceeds one without bag. Thus, we investigate the drag coefficient CD of the bagging apple by measuring drag force acting on an apple model experimentally. The shear stress on a stem under the typhoon is estimated for understanding one of mechanism for dropping apple due to the strong wind. The shear stress of a stem whose apple encounters the maximum velocity recorded at the past typhoon is estimated by the obtained CD. The drag force of the bagging apple becomes bigger than that of the apple without the bag. The bagging apple is not a rotational symmetry so that the CD is different with the different wind direction. The angle against the flow of model with the bag is changed from 0 deg. to 90 deg. to understand the influence of shape, since CD depends on the geometry. The shear force acting on the stem depends on the drag. Thus, the shear stress is larger if the drag is larger. The obtained shear stress is compared with allowable shear stress of a real tree. We suggest that there is possibility to decrease damage if we can decrease the drag of the bagging.
著者
円山 重直
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.TEP0377-TEP0377, 2014 (Released:2014-12-25)
参考文献数
30

In order to investigate the process of accident of Fukushima Nuclear Power Plants, an accident scenario of Fukushima Daiichi Nuclear Power Plant, Unit 1 is analyzed from the data open to the public. Phase equilibrium process model and adiabatic expansion model were introduced. Original data reported in the first stage of the accident were examined to clarify the behavior of the isolation condensers (ICs) which are generally believed unfunctional after the arrival of Tsunami and station blackout. The original data and observation reports verified that the so called “fail safe” system to close the valves in IC did not work properly due to the shutdown of AC power. The reports also showed the evidence that the operators injected water to the storage tank of IC. We proposed a scenario that IC was operational until approximately at 3/12 3:00, small leakage occurred at the reactor pressure vessel (RPV) at the initial stage of the accident, the RPV ruptured at 3/12 6:20, and it ruptured again in approximately at 3/12 16:00. We assumed that PCV ruptured at 3/12 3:00, and the area of rupture did not change after the hydrogen explosion occurred at 3/12 15:36. The present analysis model describes the data measured at the accident, and many evidences and witnesses reported at the early stage of the accident. We also simulated according to the scenario of Tokyo Electric Power Company (TEPCO) that the ICs did not work after the Tsunami arrival. The estimation by the present analysis agrees with the TEPCO's one, however, there are many discrepancies that cannot explain the behavior of the reactor accident.
著者
黒瀬 築 柳原 俊太郎 宮田 一司 濱本 芳徳 森 英夫
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 (ISSN:21879761)
巻号頁・発行日
vol.84, no.862, pp.17-00593, 2018 (Released:2018-06-25)
参考文献数
13

For the development of industrial heat pump system supplying a high-temperature heat source, the application of chevron type plate heat exchanger is being considered. In the present study, experiments and numerical simulation on flow characteristics in single chevron channel with chevron angle 30°, 45° and 65° were respectively performed. In the experiment, the pressure drop of the whole chevron channel and local pressure drops in each chevron channel were measured and path lines were also observed. Besides, numerical simulation reproduced the experimental results well. From both of the experimental and simulation results, it was confirmed that the pressure drop of the chevron channel became larger with increasing the chevron angle due to the strong mixing of fluids in the respective furrows of adjacent chevron plates especially in the high chevron angle channel. In such the high chevron angle channel, velocity and pressure drop gradient distributions were almost uniform in the channel width direction normal to main flow. While, in the small chevron angle channel, the fluids mixing between furrows of adjacent plates was weak and the velocity and pressure drop gradient distributions were markedly large in the width direction. Furthermore, it was found that large pressure drops occurred in the inlet and outlet regions where the channel had flow width expansion and contraction, respectively. The large pressure drops in the inlet and outlet regions affected the overall pressure drop in the chevron channel, especially in the low chevron angle channel. For each chevron angle channel, the local friction factor was obtained and the loss coefficient for the flow expansion and contraction at inlet and outlet regions was determined. Based on these results, the prediction method of overall pressure drop in the chevron channel was proposed.
著者
高野 悠一郎 長濱 大空 小山 弘貴 宮坂 明宏
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.862, pp.17-00498, 2018 (Released:2018-06-25)
参考文献数
8

In order to achieve advanced missions, it is necessary to develop satellite with large aperture reflectors. Tension truss structure is effective for reducing the weight of the antenna. However, the total strain energy of the cables increases with the number of cables. Consequently, a support structure must be sufficiently rigid to prevent deformation of the surface. The reduction of the reflector's weight can be achieved if the tensile force of the cables decreases, while maintaining the required surface accuracy. Therefore, a surface design method in which compression members are located on the cable network instead of tension cables had been proposed. It was found that cable tension can be decreased within the required surface accuracy based on an analytical estimation. However, the cable tension can be changed after an adjustment of the surface accuracy to eliminate manufacturing and assembling errors. In this study, we evaluate the effectiveness of the proposed method based on an experiment including an adjustment of the surface accuracy. We measure the surface accuracy and reaction force from a support structure using assembled cable-network models. As a result, the total cable strain energy of the cable network with compression members can be decreased by half of that without compression members.
著者
野間口 大 中切 拓 藤田 喜久雄
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.83, no.853, pp.17-00122, 2017 (Released:2017-09-25)
参考文献数
22

Generation of new concepts in product design process serves as driving force of innovation. While many methods have been proposed for supporting design concept generation, it has rarely been supported in a systematic way, because its process is done in designer's implicit thought, and therefore, it is difficult to explicitly formalize the process. This paper proposes a model of designers' thinking process in concept generation called ECF cycle. It consists of three steps, i.e., (1) Externalization: the step for representing design concepts with drawings and language, (2) Classification: the step for classifying concepts with function trees, and (3) Finding voids: the step for finding potentials of new concepts called void, which is a defect of the classification. Then, this research builds a new method of concept generation incorporating the theory of solving inventive problems (TRIZ). The method is based on a quick reference table of TRIZ principles, which helps designers to create a new concept corresponding to a void found by ECF cycle. A case study of concept generation of new running shoes is demonstrated in order to verify the ability of the proposed method.
著者
大川 真弥 滝田 好宏 伊達 央
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.812, pp.TRANS0076-TRANS0076, 2014 (Released:2014-04-25)
参考文献数
12
被引用文献数
1 2

This paper proposes a brush-cutting robot which can cut high weeds and grass automatically by hand-held brush-cutter sold in hardware store. The robot vehicle is constructed with a center articulated body, a manipulating mechanism of the brush-cutter, motor controller and sensors for self-localization. In order to get its own position continuously, two Laser Range Finders (LRF), a GPS campus and odometry encoder for each wheel are installed. Authors proposed Sensor Steering Mechanism (SSM) for the lateral guided vehicle with steering mechanism. This robot is applied SSM for the center articulated body to follow the way point line on the 2-D map. The map for self-localization is constructed with a 0.1m by 0.1m grid that is measured by the 3-D LRF. The experimental set up was developed and installed in the control program and then autonomous mowing was tested, leading to the results of running and mowing in the quadrangle of the No. 4 building of science and engineering at National Defense Academy. As a result, the proposed system achieved an error of 0.2m or less for the way point line following performance. The developed brush-cutting robot successfully completed the work without untreated area by providing an appropriate overlap by the result.
著者
新木 悠斗 上道 茜 山﨑 由大 金子 成彦
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集 (ISSN:21879761)
巻号頁・発行日
vol.84, no.861, pp.17-00507-17-00507, 2018 (Released:2018-05-25)
参考文献数
8

As a method for mining offshore gas fields, a floating production, storage and offloading (FPSO) system is attracting attention. However, sloshing in the oil-gas separator installed in FPSOs excited by sea waves is expected to cause significant difficulties. To suppress sloshing wave heights, one possibility may be to install perforated plates in a tank. In this study, a method is proposed for the accurate estimation of the first resonant wave height in the horizontal cylindrical tank with a perforated plate under pitching excitation in less time. To accomplish this purpose, the pressure loss due to the perforated plate in the open channel must be estimated accurately. Therefore, the pressure loss is modeled using steady CFD calculations considering the effects of the distribution of the flow velocity and the distribution of the inflow angle. The first order sloshing wave height is calculated in the theoretical analysis by substituting the pressure loss calculated in steady CFD. The wave heights determined using the pressure loss utilized by steady CFD are compared with the experimental value measured with a small-scale model. Using the method proposed in this study, the first resonant wave height of sloshing wave height is calculated accurately in less time.
著者
嵯峨 宣彦 手銭 聡 佐藤 俊之 永瀬 純也 遠藤 匠
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.861, pp.17-00548-17-00548, 2018 (Released:2018-05-25)
参考文献数
28

In disaster areas, rescue work by humans is extremely difficult and dangerous. Therefore, rescue work using rescue robots in place of humans is attracting attention. This study specifically examines peristaltic crawling, the movement technique used by earthworms, because it can enable movement through narrow spaces and because it can provide stable movement even in various difficult environments. Moreover, we designed each part of the robot based on required specifications and developed a real robot. We present results of motion experiments conducted with robot movement on level ground.