研究者詳細 - 髙橋　智

CiNii Books

キャビテーションの発達停留空洞を使った液体のオンライン脱気

鷲尾誠一, 高橋智, 上山恭平, 番匠谷勝之, 菊井翔太郎

日本機械学会論文集(B編) 2006年

油圧管路内脈動流における修正慣性差圧法を使った変動流量・圧力・インピーダンス同時測定の精度検証

陳恵青, 鷲尾誠一, 高橋智

日本機械学会論文集(B編) 71 ( 712 ) 2934 - 2940 2005年

Study on cavitation starting at the point of separation on a smooth wall in hydraulic oil flow

S Washio, S Takahashi, S Yoshimori

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE 217 ( 6 ) 619 - 630 2003年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PROFESSIONAL ENGINEERING PUBLISHING LTD

Cavitation starting at the point of separation on a smooth cylindrical wall was observed. At the earliest stage of cavitation, a cavity suddenly emerged at the point of separation with its upstream tip attached to the wall. Differing from incipient cavities arising at projected edges, the present one neither stayed nor formed a stable bubble on the wall. As it moved slightly downstream, the newly born cavity underwent severe deformation: i.e. it grew explosively, then split and ultimately vanished in reverse from the tail back, in as short a period as one ten-thousandth of a second. Flashing light was emitted from the cavity as it expanded, and a transient electric charge was also detected from the oil downstream in synchronization with this light emission. Moreover, a streamline extending from the point of separation was spontaneously visualized. In order to establish the reasons for this visualization, temperature distribution across the streamline was measured, revealing that heat has to be generated at the separation point. Finally, the mechanism of tensile stress and heat generation at the point of separation is theoretically discussed on the basis of Landau's analysis of a boundary layer flow along a separation line.

DOI： 10.1243/095440603321919554

定圧下における気体の油に対する拡散現象のレーザ干渉計測

滑らかな面からはく離する油の流れにおける初生空洞が停留しないキャビテーションの観察

鷲尾誠一, 高橋智, 吉森修一

日本機械学会論文集(B編) 69 ( 681 ) 1120 - 1127 2003年

高橋智, 鷲尾誠一, 顧亜雄, 冨岡正稚, 辻竜彦, 吉田篤正

日本機械学会論文集(C編) 68 ( 666 ) 635 - 642 2002年

記述言語：日本語出版者・発行元：一般社団法人日本機械学会

The diffusion process of N_2, O_2 and CO_2 into VG10 machine oil had previously been observed in such a way as measuring the pressure change of gas confined to a constant volume with the oil. Although the measured pressure changes of N_2 and O_2 had been properly predicted by the diffusion theory, it had not been the case with CO_2. With suspicion that the dependency of a diffusion coefficient on the pressure could have influenced the results for CO_2, which exhibits a much larger pressure change in the course of diffusion than N_2 and O_2, the diffusion process was otherwise observed in the present study under a constant pressure, using laser heterodyne interferometry. The diffusion of CO_2 did not agree with its theoretical prediction again, which gave birth to an idea that a convective flow might occur in the oil by the density gradient produced by gas diffusion. Then Mach-Zehnder interferometry was introduced to observe gas-oil diffusion, proving natural convection did happen some time after the diffusion started. The diffusion process of CO_2 before the occurrence of natural convection agreed well with the theoretical prediction, giving reliable values of its diffusion coefficient.

DOI： 10.1299/kikaic.68.635

CiNii Books

Study on the cavitation mechanism in hydraulic oil flow using a needle projection

S Washio, S Takahashi, S Kawahara, N Kishitani

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY 216 ( J1 ) 27 - 34 2002年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PROFESSIONAL ENGINEERING PUBLISHING LTD

Cavitation occurring at a sharp projection in a hydraulic oil flow was observed in as much detail as possible, using, variously, a microscope, a high-speed video camera, laser beams, an electric charge detector and a photomultiplier. At the tip of the needle employed as a projection, a tiny cavity as small as several tens of micrometres in length suddenly emerged and would not go away. As cavitation became more vigorous, flashes occurred intermittently around the needle and positive electrical charges were generated which synchronized with the flashing. The electrode inserted downstream from the needle detected negative charge from the oil, which was also synchronous with the flashing. Observing the needle tip with the microscope made it possible to determine exactly the moment of cavitation inception, which turned out to depend on the oil temperature as well as the downstream pressure. All these findings tend to reinforce the 'rip-off' hypothesis previously proposed by the present authors for the cavitation mechanism.

DOI： 10.1243/1350650021543861

Study on cavitation inception in hydraulic oil flow through a long two-dimensional constriction

S Washio, S Takahashi, Y Uda, T Sunahara

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY 215 ( J4 ) 373 - 386 2001年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PROFESSIONAL ENGINEERING PUBLISHING LTD

It is known that the traditional 'nucleus' theory for cavitation is incompatible with certain facts physically and experimentally recognizable in oil hydraulic flows. In order to re-examine this issue, cavitation of hydraulic oil flow through a long two-dimensional acrylic constriction was observed by various techniques: stroboscopic photography with a microscope, laser beam transmission, pressure and noise measurements, and luminescence and electrical charge detection. It was revealed that, at the incipient stage of cavitation, one stationary microscopic cavity always emerges suddenly on the inlet edge. Light emission was also observed in the cavitation together with electrostatic charge. All the findings taken together, which cannot be consistently explained by nucleus theory, lead to the following hypothesis: at the separation point a tensile force rips a liquid particle from the wall, leaving behind a vacuum space, which forms the incipient stationary cavity on the edge.

DOI： 10.1243/1350650011543619

温度勾配のある油の流れの研究（第１報粘度変化が流れに及ぼす影響）

鷲尾誠一, 南蓮, 高橋智, 比留井仁

日本油空圧学会論文集 32 ( 2 ) 27 - 32 2001年

E204 気-ゴム-油系における気体の透過量の測定(オーガナイズドセッション9 : 21世紀を拓く熱物性研究)

顧亜雄, 高橋智, 鷲尾誠一

熱工学講演会講演論文集 2001 519 - 520 2001年

記述言語：日本語出版者・発行元：一般社団法人日本機械学会

This paper deals with the measurement of quantities of gases such as nitrogen and carbon dioxide that penetrated through a rubber sheet into mineral oil by the means of combination of manometer and laser heterodyne interferometry. With N_2, the saturated solubility into the rubber is about equal to the one into the VG10 mineral oil, and diffusion coefficient is approximately 1/50 times smaller than VG10 mineral oil. The quantities of gas permeability of N_2 and CO_2 through rubber sheet increase with pressure and temperature.

DOI： 10.1299/jsmeptec.2001.0_519

CiNii Books

Study of unsteady orifice flow characteristics in hydraulic oil lines

Seiichi Washio, Satoshi Takahashi, Yonguang Yu

Journal of Fluids Engineering, Transactions of the ASME 118 ( 4 ) 743 - 748 1996年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

A technique to measure fluctuating differential pressures with high fidelity has been developed first. When applied to detecting differential pressures generated by an accelerated or decelerated liquid column, the technique turned out to be effective in finding unsteady flow rates. An experimental study has been carried out on periodically changing hydraulic oil flows through an orifice. The results support the validity of the traditional standpoint that characteristics of an unsteady orifice flow can be approximately represented by those of a steady-state one. When inspected in detail, however, a net pressure loss across an orifice in a periodical flow is delayed against a change of the flow rate. The resulting relation between the pressure loss and the flow rate describes a loop with a counter-clockwise hysteresis and a nonlinear twist along the steady-state one. Pressure recovery in a pulsating orifice flow varies with the flow rate almost along the steady-state relation, which is confirmed when the change is not fast. © 1996 by ASME.

DOI： 10.1115/1.2835504

Scopus

Measurement of transiently changing flow rates in oil hydraulic column separation

Seiichi Washio, Satoshi Takahashi, Satoshi Yamaguchi

JSME International Journal, Series B: Fluids and Thermal Engineering 39 ( 1 ) 51 - 56 1996年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Mechanical Engineers

Column separation and subsequent rejoining in an oil hydraulic line usually result in tensile waves and consequent ruptures in an oil column. In order to investigate these phenomena in more detail, it is essential to precisely measure transient flow rates in column separation and rejoining. The aim of the present work is to attain this objective: a method based on the theoretical relation of the flow rate change in a pipe with a kinetically induced pressure difference between the two separate sections. Instead of a conventional differential pressure transducer, two individual pressure gauges are used to measure pressures at the two sections and find the difference between them by subtraction. Theoretically predicted stepwise decreases of the flow rate until the column rejoining have been accurately measured, showing the effectiveness of the method. It is also pointed out that the successive calculus proposed by Zhao et al., which is expected to substantially economize the procedure to obtain flow rates from differential pressure data, may give unrealistic results.

DOI： 10.1299/jsmeb.39.51

Scopus

PSDを使った下顎の三次元運動計測装置の開発査読

鷲尾誠一, 木尾正人, 高橋智, 山下敦, 矢谷博文

計測自動制御学会論文集 31 ( 9 ) 1279 - 1287 1995年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：The Society of Instrument and Control Engineers

It becomes necessary for dental diagnosis and treatment of patients having complaints with their temporomandibular joints to precisely measure motions of their lower jaws. Although such devices as can measure one-dimensional motions of a magnet attached to an examinee's incisor or 3-dimensional mandibular movements by means of mechanical displacement transducers have already been introduced into actual service, there has been great demand for more practical and reliable ones. The expected specifications of the device are as follows; (1) high accuracy and reliability, (2) 6 degree-of-freedom measurement covering wide range, (3) light and handy with little physical burden, (4) virtually real-time data processing. The present paper intends to develop a new mandibular examination device using PSD which can meet these demands as much as possible. The characteristic relation between the output voltages of a PSD sensor and the spatial position of a target LED, which relation basically dominates the accuracy of measurements, has been obtained on the basis of geometrical optics, proving through calibration that detecting errors remain less than 0.1mm with LED positions. The device has been constructed of two light duralumin arms which support three PSD detectors and three target LED's, respectively, and are to be fastened to the examinee's upper and lower dental arches. Test measurements of plane and rotational motions of the LED arm created by an automatic pulse stage have revealed the accuracy and usefulness of the device; average deviations between measured and programed trajectories were within 0.2mm. Applications of the device to two subject examinees, one is normal and the other has a temporomandibular joint disorder, have been successful, showing its effectiveness as a examination device. With the electronic system and PC used, it took 30 seconds to conduct one whole run for an examinee, from the start to the final acquisition of graphical data display on CRT.

DOI： 10.9746/sicetr1965.31.1279

油の液柱分離における過渡変動流量の測定査読

鷲尾誠一, 高橋智, 山口智史

日本機械学会論文集(B編) 60 ( 574 ) 2081 - 2088 1994年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：The Japan Society of Mechanical Engineers

Oil column separation in which a tensile wave and the consequent rupture of an oil column can be observed provides intriguing information with cavitation study. In order to investigate the phenomena in more detail from this viewpoint, it is essential to secure a means to precisely measure transiently changing flowrates in column separation. The present paper has aimed to achieve this object ; the method is based on detecting pressure differences kinematically induced in an unsteady pipe flow. Instead of a conventional pressure difference transducer, two independent pressure gauges are used to pick up the pressure differences with high fidelity. Theoretically predicted step-like flowrates until the column rejoining have been successfully measured, showing the usefulness of the method. It is also pointed out that the algorithm adovocated by ZHAO et al. to conveniently transform sampled pressure difference data to flowrate can give unreasonable results when the transient is fast.

DOI： 10.1299/kikaib.60.2081

MEASUREMENT OF THERMODYNAMIC QUANTITIES OF MINERAL-OIL BY LOASER INTERFEROMETRY

S WASHIO, S TAKAHASHI, M KANAMITSU, A YOSHIDA

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE 208 ( 4 ) 267 - 274 1994年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：MECHANICAL ENG PUBL LTD

In previous attempts to find bulk modulus of liquids, the difficulty has always been in how to accurately measure minute volumetric changes in the fluids when pressure changes. The present paper describes the application of laser interferometry to this measurement in a mineral oil in order to develop a more reliable substitute for the conventional methods. Firstly, the basic relationship between density and refractive index of the oil was established by the use of the interference fringe method. Thereafter, the heterodyne interferometer was used to measure thermodynamic changes of state in the oil, giving adiabatic and isothermal compressibilities, specific heats at constant pressure and at constant volume, and specific heat ratio. The velocity of sound in the oil derived from adiabatic compressibility thus obtained agrees well with that determined experimentally through wave transmission tests. The same interferometer has also been shown to be applicable to the measurement of pulsating pressures in oil.

DOI： 10.1243/PIME_PROC_1994_208_126_02

ヘルムホルツ共鳴器型油圧脈動フィルタの研究査読

鷲尾誠一, 高橋智, 向畑和男, 山口智史

油圧と空気圧 24 ( 6 ) 729 - 735 1993年9月

油柱を伝わる張力波の創出と観測

鷲尾誠一, 高橋智, 小西忠孝, 守分均

日本機械学会論文集(B編) 58 ( 547 ) 779 - 784 1992年

記述言語：日本語出版者・発行元：The Japan Society of Mechanical Engineers

Tensile stresses in liquids are not necessarily a familiar idea in fluid engineering, so much less accepted is the reality of tensile waves travelling through a liquid continuum. The present paper aims at giving evident proof for the premise. In a pipe with its end closed, branching from the main line where column separation is started, alternating tensile and compressive waves have been beautifully created and measured. It has turned out that the ordinary viscous wave equation can properly predict the time profiles of the masured pressures, which reveals that a tensile wave propagates in oil at the same speed as a compressive one. The observations by use of a transparent acrylic tube have also revealed the rupturing of an oil column under an excessive transient tensile stress; in the aftermath there has emerged a bubble which is usually mistaken for the cause of cavitation, but is actually brought about by diffusive separation of gas from the oil into the rupture.

DOI： 10.1299/kikaib.58.779