Hiroshi Katakura

Interfacial waves of the magnetic fluid in vertical alternating magnetic fields

Abstract The stability of the surface of a magnetic fluid layer under the influences of vertical alternating magnetic fields was investigated experimentally and analytically. Two kinds of waves were excited on the surface and the critical conditions for the onset and the wavelength of these waves were obtained.

Multi-step positioning control using a binary digital pneumatic-cylinder system

This paper presents an analysis of the dynamics of binary digital pneumatic-cylinder systems, which was undertaken to achieve multi-step positioning control. Based on an experimental system and a new algorithm for numerical analysis, the positioning control problem was investigated by means of simulations and experiments under various load conditions. Two methods are proposed to improve the transient response during positioning: timing control and braking control.

An experimental research on water-based hydraulic fluid. (Characteristics of a fixed-delivery vane pump)

Recentlyt he social demands for energy conservation and product safety of hydraulic equipments are becoming higher and higher. Water-based fire-resistant hydraulic operating fluids are thought to fit to these demands. In this research some effects of the water contents of water-glycola nd O/W emulsion, w hich are typical water-based fire-resistant hydraulic operating fluids, on the characteristics of a fixeddelivery vane pump, made to be used mainly with the petroleum-based hydraulic operating fluids, were studied. Following are some of the results of the experimental research presented in this report. (1) Total efficiency of the test pump was found to remain unchanged practically and to be more than or equal to 70% during its test drive of 250 hours using the water-glycol having less than or equal to 80 wt% water contents. (2) Test pump damage due to abrasion etc. was hardly found during the 250 hours test drive with water-glycol having less than or equal to 70 wt% water content except for the exceeding small and temporary damage at the beginning of the test.