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Emergency generators are expected to work in a disaster-related black-out, and emergency fuel supply to the generators at the companies and the residences in affected areas is important. Although some companies build a system of emergency fuel supply, the unique features of fuel transport such as the necessity of some skills and licenses make it difficult to establish an effective emergency response scheme. In order to overcome the problems, the difficulties on emergency fuel supply management are listed up from some case studies. The results clarified the topics to be considered in future studies., 本検討は，2019年度関西大学研究拠点形成支援経費において，研究課題「大規模地震発生時の燃料供給ネットワーク構築に関する研究」として研究費を受け，その成果を公表するものである．

In this paper, we consider transporting a liquid container on a cart containing an active vibration reducer, which has a parallel linkage mechanism with six degrees of freedom. Sloshing in the liquid container is generated by the movement of the cart running on an uneven road. To damp the sloshing, the liquid container is tilted and moved horizontally by using the active vibration reducer. The damping control system consists of both disturbance suppression control (DS) and a frequency-dependent optimal servo (FS). The acceleration added to the container while the cart is running on uneven roads is reduced by using DS. The residual sloshing is suppressed by using FS. In this study, only (1, 1) mode sloshing is modeled as a pendulum-type sloshing model in the control system. When a suddenly changing acceleration is added to the liquid container, higher-mode sloshing that is not modeled in the control system is easily generated and causes spillover. DS is also useful to avoid this phenomenon. The weighting matrix of the quadratic performance index for FS is efficiently determined using a genetic algorithm (GA). The amplitude of sloshing is considered for GA fitness. Further, the usefulness of the proposed control system is verified through an experiment. Using both DS and FS, the damping performance improves by approximately 79% compared to without control, and 18% compared to using FS alone.

This paper presents a method for damping sloshing in a liquid container during its transfer by a cart that is equipped with an active vibration reducer with six-degree-of-freedom parallel linkage. Sloshing is generated during the liquid container transfer. To damp this sloshing, it is tilted and horizontally moved by the active vibration reducer. The reducer is controlled by a linear quadratic regulator. A weighting matrix of the quadratic performance index is optimized using a genetic algorithm. Gain scheduling is used to apply it to any liquid level of the container. The cart is driven along a straight path on a horizontal plane. The usefulness of the control system is verified through a simulation and experiment.

Fluid behavior in microgravity (µg) is different from in ground gravity since surface tension and wetting are dominant in µg conditions. In propellant tanks for artificial satellites and future on-orbit spacecraft, sloshing due to disturbance and settling behavior from changes in acceleration have to be understood for the design of the propellant supply system and attitude control system. In this paper, we observed sloshing behaviors in cylindrical containers in µg conditions created by a drop tower facility. In order to investigate the effects of the contact line velocity on dynamic contact angle, we measured dynamic contact angle using a capillary tube. CFD analysis introducing Cox’s equation in consideration of capillary experimental results were also conducted and these results were compared with µg experimental results. Regarding the experimental results, the diameter of the test tank, excitation acceleration, and kinematic viscosity were found to have a significant effect on sloshing behavior in a µg condition. Regarding the comparison between the CFD analysis results and the experimental results, there was a slight difference in the wave shape and the time required for the liquid to reach the top of the test tank. Conversely, there was a qualitative agreement between the fluctuation period and the approximate shape of the liquid surface over time.

This paper proposes a damping control of sloshing in a cylindrical container with a dual swing-type active vibration reducer on a wheeled mobile robot (WMR). The WMR runs along a straight and curved path on a horizontal plane and a straight path on a slope. The container is mounted on the active vibration reducer. Two laser displacement sensors are used to observe the liquid level at the back measuring point and the right side one. The container can be independently tilted in the running direction and the orthogonal direction by the active vibration reducer. A sloshing model is obtained from the spherical pendulum-type sloshing model, which approximately expresses (1, 1)-mode sloshing. The sloshing model is used to design a damping control system. The control system of the active vibration reducer is designed with an inverse model of sloshing and an optimal regulator with a Kalman filter. The WMR is driven by an acceleration pattern designed with an input shaping method. The usefulness of the proposed method is demonstrated through simulation and experimental results.

This paper proposes a damping control of sloshing in a cylindrical container with a swing-type active vibration reducer on a wheeled mobile robot (WMR). The WMR runs along a straight path on a horizontal plane. The container is mounted on the active vibration reducer. A laser displacement sensor is used to observe the liquid level in the container. The container can be tilted in the running direction by the active vibration reducer. A sloshing model is obtained from a spherical pendulum-type sloshing model, which approximately expresses (1, 1)-mode sloshing. The sloshing model is used to design a damping control system. The control system of the active vibration reducer is designed with an inverse model of sloshing and an optimal regulator with a Kalman filter. The WMR is driven by an acceleration pattern designed with an input shaping method. The usefulness of the proposed method is demonstrated through simulation and experimental results.

2003年北海道十勝沖地震ではスロッシングにより石油タンクの浮屋根が被災し、タンクの炎上に至った。今後、東海・東南海・南海地震においても同様の被害が予測され、その対策が緊急かつ重要なものとなっている。本研究では、スロッシングを防止するためダンパーを提案するとともに、その効果を検証するため、小規模模型実験および数値解析を行った。その結果、提案した抑制機構が小規模模型タンクにおけるスロッシング抑制に有効であることおよびVOFを用いた数値解析によりスロッシング抑制挙動を精度良く予測可能であることが分かった。, The liquid sloshing in petroleum tanks is one of severe problem against huge earthquakes such as the Tokai Tonankai and Nankai earthquakes. In this study, we are developing a damper to reduce sloshing. The damper consists of partitions with slits which gives resistance to liquid moving in the tank. Model experiment and numerical simulation are performed to study the effect of the damper. As a result, the experimental results show that the present dumper is effective to reduce sloshing of cylindrical tank. And the numerical results show that our numerical simulation method can accurately simulate the sloshing behaviors of the cylindrical tank in which the dumper is installed.

金沢大学理工研究域地球社会基盤学系, Japan is situated in one of the most active seismic zones in the world. Many strong earthquakes of seismic intensity 5 or more have occurred in Japan within a short period after the 1995 Hyogoken-Nanbu Earthquake. In earthquakes of seismic intensity 5 or more, the long-period component of seismic motion is propagated over 200 km or more distances from the focus, and some of such earthquakes were noticeable in Osaka City even though the city was situated distantly from the focus. Although no Osaka Municipal Waterworks Bureau (OMWB) suffered physical damage from these earthquakes, unusual phenomena such as an abrupt increase in flow rate and a decrease in water pressure were observed right after the occurrence of the earthquake.The present study studies this phenomenon, focuses on sloshing in water receiving tanks as a possible cause of the phenomenon, and discusses causal relationship from the observed data. The relationship between the amount of sloshing in the water receiving tank and the frequency characteristics of seismic motion is analyzed by using seismic wave data observed in OMWB., 水道供給システムでは地震が発生した直後, システムに物理的なダメージが無くても急激な流量増加と水圧減少という異常挙動現象を発生することがある. この異常挙動現象は, 大規模漏水が発生した現象に酷似しており, 管路被害による漏水なのか異常挙動によるものかを確認することが困難であるため, 地震被害把握等の災害復旧過程における初動体制確立に影響を及ぼす可能性がある. 本論文では, これらの原因と考えられるやや長周期地震動による受水槽のスロッシングと異常挙動の関係について考察するとともに, モンテカルロシミュレーションを用いた管網計算により, 水道供給システムへの影響を定量的な分析を行った.

金沢大学理工研究域地球社会基盤学系, 水道供給システムでは, 地震が発生した直後, システムに物理的なダメージが無くても急激な流量増加と水圧減少という異常挙動を発生することがある.この現象は一時的であるものの, 発生中は水道供給システムを機能低下させることがある.本論文では, この影響について観測結果を報告するとともに, これらの原因と考えられる受水槽のスロッシングについて, 観測データから因果関係を解明した.さらに, 大阪市で観測された地震波形を用い, 受水槽のスロッシングによる水面最大変位と地震動の振動数特性との関係を分析するとともに, 発生が予想される東南海・南海地震についても, 予測地震動を利用して水道供給システムへの影響を分析した., This paper has tried to reveal the cause of irregular surge of water distribution volume and irregular decrease of water pressure respectively just after an earthquake. First the cause of a surge in water distribution volume is examined in a statistical manner based on the observation data by Osaka Waterworks Bureau (OWWB). Next the movement of water inflow into the water receiving tanks just after earthquakes are numerically examined using acceleration waveform collected by OWWB's earthquake monitoring system. The relationship between the sloshing phenomenon caused to water receiving tanks and a sudden surge of water distribution volumes was considered. Furthermore, the sloshing phenomenon of water in receiving tank was examined using hypothetical acceleration waveform of Tokai-Tonankai earthquake.

Numerical simulator for propellant feed systems in liquid-propellant rocket engines based on CFD is under development for supporting H-2A rocket and next generation rocket development. This simulator consists of turbo pump system simulator and tank system simulator. In this paper, the tank system simulator based on CIP-LSM, which computes free surface behavior, temperature and pressure in rocket propellant tank, is presented. Also, the computed results of 2D sloshing and broken dam problems are presented to assess the accuracy of the solver for problems with strong deformation of the fluid. The results were in good agreement with other published data and experiments. As a result, it was clear that CIP-LSM is an effective method for predicting strong deformation of free surface flows., 資料番号: AA0049056002, レポート番号: JAXA-SP-05-010

After the Tokachi-0ki earthquake, earthquake proofing of cylindrical tanks are demanded. In particular, the measure against a sloshing is demanded. However, there is not a method obtaining effective result in an actual tank. In this paper, we propose a wave height reduction method and explain about effects of it. This proposed method is used a support and a flat board as an instrument. At first, we performed an experiment of a shaking table using the cylindrical tank's model. We examined the wave height and the wave pressure of the sloshing. When we used the proposing method, we measured the wave height and the wave pressure too. Next, in numerical analysis, we calculated sloshing wave height in a condition same as an experiment and examined the propriety of numerical analysis.

MU-300型航空機のパラボリックフライト中に得られる微小重力状態での円筒容器中液体の安定性を研究した。微小重力下における生物学的な溶液の取り扱い方法を評価することが一つの目的である。内径3.4〜20mmのガラスまたはアクリル樹脂製円筒に、生理食塩水または70％エタノール溶液を半分量満たす。0.1-1.0Gの衝撃によって発生するスロッシングを観測した。この衝撃の大きさは、人為操作の加速度と同等と考える。パラボリックフライト中、円筒内径が7mm以下の場合は水の表面は安定であった。内径5mm以下のチューブになると、微小重力下でもこの衝撃に対して確実に表面を保った。微小重力下での衝撃の後のスロッシングは、管径の大きいものほど顕著であった。表面張力は、この封入液の微小重力下での主要な安定力と考えられる。微小重力下での少量の液体の取り扱いは、操作上、適切な条件が付けられるならば、ピペットや小型試験管のような実験室用器具類で成果を挙げうることを、この実験は示唆している。, The stability of liquid in cylindrical containers was studied under microgravity achieved via parabolic flights of MU-300 aircraft. An aim of this experiment is to evaluate the handling methodology for biological solutions under microgravity. Glass or acrylic cylinders of 3.4-20 mm in inner diameters were half filled with physiological saline or 70 percent ethanol solution. The in-flight measurements were made by observing the sloshing induced by lateral impacts in a range of 0.1g to 1.0g which may be equivalent to a magnitude of acceleration caused by human casual handling. The liquid surface remained stable during the parabolic flight in case of smaller diameter than 7 mm with water. The tubes smaller than 5 mm in diameter could hold the surface securely against the impact even under the microgravity. The sloshing under the microgravity after the impact was more remarkable in larger tubes. The surface tension appeared to be the major stabilizing force keeping the contained liquid under microgravity. This experiment suggested that the handling of small amount of aqueous solutions may be performed under the microgravity with an apparatus similar to laboratory equipment such as pipettes and small test tubes, if an appropriate operational containment is available., 資料番号: AA0000737005, レポート番号: NASDA-TMR-960020

This paper presents a control system to damp sloshing in a liquid container during its transfer in a cart equipped with an active vibration reducer having a parallel linkage with six degrees of freedom. Sloshing is generated during the liquid container’s transfer. To damp this sloshing, the active vibration reducer tilts and horizontally moves the container. The reducer is controlled by a reference following control and optimal servo control. When a large liquid container is used, higher-mode sloshing that is not modeled in the control system is easily generated and causes spillover. The reference following control was adopted to avoid this phenomenon. The weighting matrix of the quadratic performance index for the optimal servo control is optimized with a genetic algorithm (GA). The amplitude of sloshing is considered for GA fitness. In this study, a cart was driven along a straight path on a horizontal plane, and only (1, 1) mode sloshing was modeled in the control system. When the optimal servo control was used alone in a damping control experiment, the active vibration reducer and liquid container vibrated violently because of spillover. On the other hand, when the optimal servo control and reference following control were used together, the liquid container did not vibrate, and sloshing in the container was damped by the active vibration reducer.

通信技術の発達に伴って、成層圏プラットフォームとしての飛行船の可能性が注目されている。飛行船は19世紀後半に発明され、第1次世界大戦前後に大飛躍を遂げたが、固定翼航空機の発達に伴って衰退した。現代では、主として宣伝広告や観光飛行に小型飛行船が使われている。しかしながら前進速度で揚力を得ている固定翼航空機と異なり、前進速度なしでも搭載ガスの浮力で空中に浮揚する飛行船は高空での定点滞空により適していると考えられる。高度20km付近の風の弱い成層圏に複数の飛行船を定点滞空させ、通信中継、放送、地上監視などのプラットフォームにしようというのが、成層圏プラットフォームのコンセプトである。このコンセプトのわが国における推進の一環として、ミレニアム・プロジェクトにおいて成層圏滞空試験機および定点滞空試験機の開発が現在進められている。これらの開発において技術課題の解決が図られているが、成層圏プラットフォームそのものの開発では高高度を定点滞空するために更なる極限設計が求められる。従って、これらの試験機で明らかになった技術課題だけでなく、成層圏プラットフォーム開発における技術課題についても研究を進めておくことが必要である。本論文では、成層圏プラットフォームの全般的な技術課題に触れるのではなく、プラットフォームとしての飛行船の構造設計に限定して課題を紹介する。本書で取り上げている項目は、スペック、構造様式、膜材、荷重、応力、スロッシング、試験法である。, Attention is being drawn to the possibility of the airship as a stratospheric platform, as communication technology develops. The airship was invented toward the end of the 19th century, and subsequently made rapid progress, falling into a rapid decline however with the remarkable advance of aircraft technology. Nowadays only small air-ships are utilized, for sightseeing and advertising. Airships are thought more suitable when the purpose is to remain stationary at high altitudes, because they gain lift by gas buoyancy, in contrast to aircraft, which gain lift by advance speed. In the concept of the stratospheric platform, many airships are floated in the stratosphere serving as platforms for communications, broadcasting or ground observation. As part of efforts to promote this concept, a Ground-to-Stratosphere Flight Test Vehicle and a Low-Altitude-Stationary Flight Test Vehicle are currently being developed. Many technical issues have emerged in the development of these vehicles. However a much severer design will be required to allow stationary flight at around an altitude of 20 km in the development of the stratospheric platform. Therefore research should be performed not only on the technical issues identified in the current test vehicle development, but also on issues in the stratospheric platform development. This memorandum discusses the design issues of an airship structure rather than the overall technical problems of the stratospheric platform. The topics covered are airship specifications, structure style, envelope materials, loads, stresses, sloshing, and test methods., 資料番号: AA0046102000, レポート番号: NAL TM-772

The sloshing response of a large water reservoir under the seismic acceleration was investigated by using a flow visualization technique, PIV measurement and numerical simulation. Transient flow pattern was observed by a high speed CCD camera and micro bubbles were analyzed in order to obtain the flow velocity with cross correlation method. The impact pressure of sloshing fluctuation was measured with pressure transducer mounted on the top plate. The pressure history was digitized and averaged for ensemble of sloshing cycle. Numerical simulation also performed for the tank design. A practical seismic wave was used in the numerical calculation. Consequently, a severe criteria for the tank design was deduced from the present results.

Sloshing impact of the water reservoir under earth-quaking was investigated with flow visualization technique, PIV measurement and numerical simulation. Transient flow pattern was observed by CCD camera and micro bubbles were analyzed in order to obtain the flow velocity with cross correlation method. An impact of the sloshing was measured with pressure transducer mounted on the top plate. The pressure history was digitized and averaged for ensemble of sloshing cycle. The maximum of the impact and corresponding water surface profile was discussed in order to study the impact mechanism. Numerical simulation also performed for the tank design. Numerical result shows a good agreement with experimental result. A similarity law of the sloshing was discussed in the test.

自由表面をもつタンク内液体の運動解析の手法として液体重心の動きを追うアルゴリズムLAMPSがある。そのオリジナルプログラムにおいては液体の減衰は実験値から入力されるため,予測計算に使うには汎用性に欠けていた。本報告ではこのアルゴリズムの欠点であった減衰力の入力について,減衰を理論的に導き,その実用性を既存の試験結果により確認した。, The dynamic behavior of liquid propellants in launch vehicles and spacecraft has been of great importance in past current generation vehicle designs. A method to theoretically estimate the viscous dissipative force from liquid propellants transient motion in tanks is present. The estimation algorithm is combined into the LAMPS(Large AMPlitude Sloshing) algorithm, where the dissipative values have been approximated from test data. Analytical predictions show excellent correlation with existing test results., 資料番号: NALTR1095000, レポート番号: NAL TR-1095

水の入った円筒形容器を，あるモードの固有振動数に近い振動数で，水平方向に正弦波的に加振する実験を行なった．そして，加振振幅がある程度以上大きく，且つ，加振振動数が固有振動数よりも少し小さい場合に，不規則挙動を示す大振幅水面波があらわれることを示し，その統計的性質を調べた．さらに，この挙動が，弱非線形性及び一定減衰率での線形減衰の仮定に基きMilesにより導かれた4変数の連立常微分方程式の示すカオス的挙動に非常に近いものであることがわかった．

application/pdf, Article, 大阪府立工業高等専門学校研究紀要, 1987, 21, p.73-80