Papers - Sawada, Tatsuo

Frequency analysis of semi-active tuned magnetic fluid column damper with two electromagnets

Kazuki Ikari, Hideaki Masuda, Toshiyuki Oyamada and Tatsuo Sawada

Materials Science Forum (Trans Tech Publications, Switzerland)  792   275-280 2014.08

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1662-9752

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We designed a new semi-active Tuned Liquid Column Damper (TLCD) which uses Magnetic Fluid as its working fluid (MF-TLCD). We investigated the damping characteristics of MF-TLCD which has the two electromagnets, and considered transition of the natural frequency that is strongly related to the damping performance. We presented the momentum equation of MF-TLCD, and solved it numerically. Numerical results were compared with experimental results.

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Investigation of inner structure in magnetic fluid under compression using ultrasonic measurement

Ahmad Isnikurniawan, Yasuhiro Fujita, Sachio Tanimoto and Tatsuo Sawada

Materials Science Forum (Trans Tech Publications, Switzerland)  792   147-152 2014.08

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1662-9752

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Ultrasonic propagation velocity in a magnetic fluid under compression was investigated. Ultrasonic propagation velocity in a magnetic fluid changed with the magnetic flux density and the compressive force. This change is related with cluster formation in a magnetic fluid. Experiment results indicated that cluster formation in a magnetic fluid seemed strongly affected by compressive force.

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Characteristics of ultrasonic propagation in a magnetic functional fluid under AC magnetic fields

Yasuhiro Fujita, Ahmad Isnikurniawan, Sachio Tanimoto, Kanta Moriyama, Tatsuo Sawada

Journal of the Japan Society of Applied Electromagnetics and Mechanics (The Japan Society of Applied Electromagnetics and Mechanics)  22 ( 2 ) 280 - 285 2014.06

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0919-4452

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This paper reports experimental studies about anisotropy and attenuation as characteristics of ultrasonic propagation in a magnetorheological fluid (MRF) under AC magnetic fields. Parameters of this studies are magnitude of AC magnetic fields, frequencies of AC magnetic fields and angles between directions of ultrasonic propagation and magnetic field. As results of change rate of sound velocity, MRF has characteristics of time dependence, frequencies dependence and anisotropy under AC magnetic fields. Also, length of clusters in MRF became short with increase of frequencies of AC magnetic fields. Attenuation decreased with increase of the angles between directions of ultrasonic propagation and magnetic field. But, attenuation did not change with increase of frequencies of AC magnetic fields.

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Damping characteristics of semi-active tuned liquid column damper with a magnetic field

Toshiyuki Oyamada, Hideaki Masuda, Kazuki Ikari and Tatsuo Sawada

Magnetohydrodynamics (Institute of Physics, University of Latvia)  49 ( 3-4 ) 516 - 519 2013.12

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0024-998X

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We designed a novel semi-active TLCD (Tuned Liquid Column Damper) that uses a magnetic fluid (MF) as a working fluid. Two electromagnets were used and a magnetic field was applied symmetrically to both sides of the magnetic fluid column. The frequency response of the MF-TLCD apparatus was measured, and the influence of magnetic fields on the natural frequency of the magnetic fluid column was investigated.

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Effect of a magnetic field on sloshing in a two-layer fluid

Shunsuke Kaneko, Takayoshi Ishiyama, Shin-ichiro Takemoto and Tatsuo Sawada

Magnetohydrodynamics (Institute of Physics, University of Latvia)  49 ( 3-4 ) 520-524 2013.12

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0024-998X

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Sloshing of a two-layer fluid with a water based magnetic fluid and a silicone oil was investigated. A magnetic field was applied by two permanent magnets, and these were placed near the interface between a magnetic fluid and a silicone oil. Several frequency response spectrum were received in each experimental conditions. Changes in the sloshing behaviour of the two-layer fluid with several magnetic fields were reported.

Ultrasonic characteristics of a magnetic fluid under compressive force

Yasuhiro Fujita, Ahmad Isnikurniawan, Sachio Tanimoto and Tatsuo Sawada

Magnetohydrodynamics (Institute of Physics, University of Latvia)  49 ( 3-4 ) 368-371 2013.12

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0024-998X

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The characteristics of the inner structure of a magnetic fluid (MF) under high pressure were investigated experimentally. The ultrasonic propagation velocity was changed with the application of magnetic fields and pressure. The change was related to cluster formation in the MF fluid. Based on the experimental results, the effect of pressure on the inner structure in MF was analyzed.

Investigation of ultrasonic properties of MR fluid under various sweep rates of magnetic field

Ahmad Isnikurniawan, Yashuhiro Fujita, Sachio Tanimoto and Tatsuo Sawada

Magnetohydrodynamics (Institute of Physics, University of Latvia)  49 ( 3-4 ) 430-433 2013.12

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0024-998X

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The ultrasonic propagation velocity of MR fluid under various magnetic field sweep rates was measured. A magnetic flux density was applied from 0 to 400 mT over different lengths of time. On the basis of the experimental results, the effect of the magnetic field sweep rates on the cluster formation of MR fluid was analyzed.

Vibration Analysis of the Tuned Liquid Column Damper with a Magnetic Fluid

Hideaki Masuda, Toshiyuki Oyamada, Kazuki IKari and Tatsuo Sawada

Journal of the Japan Society of Applied Electromagnetics and Mechanics (The Japan Society of Applied Electromagnetics and Mechanics)  21 ( 2 ) 228-233 2013.06

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0919-4452

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We present the equation of motion of a MF-TLCD (Tuned Liquid Column Damper with a Magnetic Fluid), and solved it numerically using a 4th-order Runge-Kutta method. Using the numerical results, we demonstrate the frequency responses of a MF-TLCD and the effect of the magnetic field on the natural frequency of a MF-TLCD. We also compare numerical results with experimental results, and show that they are coincident qualitatively.

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Variation of forced convective heat transfer in rectangular duct flow of a magnetic fluid under magnetic field

Masaaki Motozawa, Tsukasa Sekine, Tatsuo Sawada and Yasuo Kawaguchi

Journal of Physics: Conference Series (IOP Publishing)  412   012025(11pp) 2013.02

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1742-6588

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Variation of forced convective heat transfer in a rectangular duct flow of a magnetic fluid under a magnetic field was investigated experimentally. The results of the experiments show that in the case of laminar flow of the magnetic fluid, when a magnetic field is applied to a magnetic fluid flow, heat transfer locally increases in the region where the magnetic field exists. In contrast, in the turbulent flow of the magnetic fluid, heat transfer is not enhanced but reduced. In order to better understand this heat transfer phenomenon, we measured the velocity distribution of magnetic fluid flow by the Ultrasonic Velocity Profile (UVP) method. In the case of laminar flow, the result shows that the flow velocity at the center of the rectangular duct decreases and the velocity gradient in the near-wall region increases. Moreover, we calculated the flow resistance under a magnetic field by measurement of the pressure gradient, and the relationship between heat transfer and flow resistance was discussed.

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Effect of an applied magnetic field on sloshing pressure in a magnetic fluid

Shunsuke Kaneko, Takayoshi Ishiyama and Tatsuo Sawada

Journal of Physics: Conference Series (IOP Publishing)  412   012018(7pp) 2013.02

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1742-6588

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Dynamic pressure response in an oscillating rectangular container filled with a magnetic fluid under a horizontal magnetic field was discussed. An investigation was made experimental approach based on the measurement of pressure at several points by pressure transducers and the real-time computation of a discrete Fourier transform.

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Experimental study on damping characteristics of the tuned liquid column damper with magnetic fluid

Hideaki Masuda, Toshiyuki Oyamada and Tatsuo Sawada

Journal of Physics: Conference Series (IOP Publishing)  412   1-9(012049) 2013.02

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1742-6588

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We designed a novel semi-active damper using a magnetic fluid as a working fluid of the tuned liquid column damper (MF-TLCD). Experiments were performed to analyze the effect of a magnetic field on natural frequencies of the MF-TLCD. Based on the experimental results, relations among setting positions of an electromagnet, strength of magnetic field, and changes of a natural frequency were discussed.

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Investigation of cluster growth in MR fluids using ultrasonic wave propagation

Ahmad Isnikurniawan, Jun Kuroiwa, Shunnosuke Abell and Tatsuo Sawada

Journal of Physics: Conference Series (IOP Publishing)  412   012019(5pp) 2013.02

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1742-6588

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We carried out experiments by applying different magnetic field (M/F) sweep rates to MR fluid. The ultrasonic propagation velocity was measured and the change of ultrasonic propagation velocity was calculated for various M/F sweep rate. The relation between the change of ultrasonic propagation velocity and M/F sweep rate was discussed.

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Application of ultrasonic technique for magnetic functional fluids

Tatsuo Sawada, Ahmad Isnikurniawan, Masaaki Motozawa, Muhammad Agung Bramantya

Final Report of Research Committee on Integration of Fluid Power Systems with Functional Fluids (The Japan Fluid Power System Society)     65-69 2012.09

Research paper (conference, symposium, etc.), Joint Work

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日本フルードパワーシステム学会の「機能性流体を核としたフルードパワーシステムの融合化に関する研究委員会」研究成果報告書を分担執筆した。

Experimental investigation on heat transfer characteristics in rectangular duct flow of a magnetic fluid under magnetic field

Masaaki Motozawa, Jia Chang, Tatsuo Sawada and Yasuo Kawaguchi

International Journal of Applied Electromagnetics and Mechanics (IOS Press)  39 ( 1-4 ) 583-588 2012.09

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1383-5416

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Forced convective heat transfer characteristics in a rectangular duct flow of a magnetic fluid under a magnetic field were investigated experimentally. Experiments were performed in which the magnetic field intensity was changed from 0 mT to 500 mT. The Reynolds number based on the hydraulic diameter was set to 820 (laminar flow), 1630 and 2450 (turbulent flow). The magnetic fluid in the rectangular duct was heated with a uniform heat flux. The results of the experiments showed that in the case of laminar flow of the magnetic fluid, when the magnetic field is applied to the magnetic fluid flow, the heat transfer coefficient increases locally in the region where the magnetic field exists. In contrast, in the turbulent flow of the magnetic fluid, heat transfer is not enhanced, but slightly decreases.

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Cluster formation in two-dimensional channel flow of a magnetic fluid under uniform magnetic field

Akihiro Nakamura, Satoshi Suzuoka and Tatsuo Sawada

International Journal of Applied Electromagnetics and Mechanics (IOS Press)  39 ( 1-4 ) 563-568 2012.09

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1383-5416

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The two-dimensional channel flow of a magnetic fluid was experimentally investigated. When a magnetic field is applied to a magnetic fluid, ferromagnetic particles aggregate along the direction of the magnetic field and form clusters. The pressure drop of the magnetic fluid flow changes according to cluster formations. The effect of the applied magnetic field on the pressure drop was determined. The ultrasonic propagation velocity was also measured to clarify the effect of cluster formations.

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Effect of a uniform magnetic field on magnetorheological fluid under an impact load

Yoshitaka Moroka, Ahmad Isnikurniawan, Hiromichi Ohba and Tatsuo Sawada

International Journal of Applied Electromagnetics and Mechanics (IOS Press)  39 ( 1-4 ) 569-573 2012.09

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1383-5416

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We carried out an impact experiment in order to investigate the influence of magnetic field intensity and inner diameter of the orifice on MR fluid motion under an impact load. The experiment was conducted by measuring the piston displacement. From the piston displacement, its velocity and acceleration were calculated.

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Ultrasonic propagation attenuation in an MR fluid under an external magnetic field

Ahmad Isnikurniawan, Jun Kuroiwa, Shunnosuke Abell and Tatsuo Sawada

Journal of the Japan Society of Applied Electromagnetics and Mechanics (Japan Society of Applied Electromagnetics and Mechanics)  20 ( 2 ) 434-439 2012.06

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0919-4452

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Experiments were performed to measure how the ultrasonic propagation attenuation in an MR fluid under an external magnetic field was affected by temperature, elapsed time, magnetic field intensity, magnetic field angle, removal of the magnetic field, and hysteresis. The influence of the clustering structures on change of ultrasonic propagation attenuation in MR fluids is discussed.

Dynamic pressure change of a magnetic fluid in a lateral oscillating container

Shunsuke Kaneko, Jean Klingler, Takayoshi Ishiyama and Tatsuo Sawada

Journal of the Japan Society of Applied Electromagnetics and Mechanics (Japan Society of Applied Electromagnetics and Mechanics)  20 ( 2 ) 416-421 2012.06

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0919-4452

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Dynamic pressure change of a magnetic fluid in a lateral oscillating container was investigated. An experimental approach based on the measurement of pressure at several points by small disc-type pressure transducers was used. Several frequency response spectra are received. These results indicated that the free surface disturbance caused by the sloshing was suppressed by the applied magnetic field.

Experimental investigation into the effect of a magnetic field on magnetorheological fluids under an impact load

Ahmad Isnikurniawan, Yoshitaka Moroka, Hiromichi Ohba and Tatsuo Sawada

Materials Science Forum (Trans Tech Publications, Switzerland)  721   179-184 2012.06

Research paper (international conference proceedings), Joint Work, Accepted,  ISSN  1662-9752

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We perform a qualitative analysis to investigate the effect of a magnetic field on MR fluids under an impact load. An experimental apparatus that consists of a drop-test tower was developed to simulate the impact load, and an MR fluid in a U-pipe was subjected to the impact load via a piston rod. We measured the displacement and velocity of the piston rod, and the influence of a given magnetic field on the behavior of MR fluids under an impact load is discussed.

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A study on the inner structure of magnetorheological fluids by image processing

Muhammad A. Bramantya, Hiroki Takuma, Jun Kuroiwa and Tatsuo Sawada

Journal of the Japan Society of Applied Electromagnetics and Mechanics (Japan Society of Applied Electromagnetics and Mechanics)  19 ( Supplement ) S228-S233 2011.09

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0919-4452

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This paper would be elaborate experiment result of inner structure of MR fluid by means of visualization using optical microscope and CCD camera. The results show the rate of cluster formation is increase when the strength of magnetic field is increase, means that cluster formations are more robust and larger size for high magnetic field. The investigation of inner structure of MR fluids using image processing was successful. The growth of cluster formation is clearly seen in our image analysis. The cluster develops more robust when the magnetic field intensity is increase.