著者

鵜沢 潔 池尾 茂

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.51, no.472, pp.4230-4238, 1985-12-25

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This paper deals with the laminar oscillatory flow of an incompressible fluid through a slightly convergent tube. The velocity distributions in the convergent tubes, whose convergent angles are in the range of 2~4°, are measured by a Laser Doppler Velocimeter. The flow in the convergent tube is numerically analysed by a finite difference method (SOR), without neglecting the convective terms in the Navier-Stokes equation. Experimental results agreed well with the numerical ones. The velocity profile of a laminar oscillatory flow in the convergent tube is quite different from the velocity profile in a straight tube of circular cross-section, even if the convergent angle is very small. The instantaneous pressure distribution in the convergent tube is uniform at each cross section as in a straight circular tube.

著者

馬 衛東 池尾 茂

出版者

The Japan Fluid Power System Society

雑誌

日本フルードパワーシステム学会論文集 (ISSN:18803121)

巻号頁・発行日

vol.35, no.1, pp.15-21, 2004-01-15

参考文献数

6

被引用文献数

1 1

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In order to reduce energy consumption, secondary control systems have been applied to many types of equipments. In lifting equipment and press machines using hydraulic cylinders, a hydraulic transformer is used, instead of a valve as a control component for motion control and for recovering potential energy of load. The transformer is a combination of a variable displacement pump/motor, which is a secondary controlled element, and a fixed displacement pump/motor. In this paper the energy-saving effect of the transformer is studied. Multiple closed loop controllers, consisting of displacement feedback of variable pump/motor, speed feedback of the cylinder and position feedback of the cylinder are used. The efficiency and energy consumption when the cylinder is driven up and down is calculated by simulation. Simulation results show that considerable energy saving is achieved by accurately choosing load ratio, circuit type and supply pressure.