2006 年 72 巻 716 号 p. 949-955
A basic study of a gap flow in a closed piston-cylinder system of ER fluid was carried out. The purpose of this study is to elucidate flow behavior of ER fluid in the piston-cylinder system. The electric field is applied between inner wall of the cylinder and outer wall of the piston, and the pressure difference between upper and lower chamber of the piston is measured. Theoretical formula of pressure difference was obtained by the one-dimensional assumption of the flow in the gap of cylinder. Furthermore, simulation cord is developed in the present study based on the finite volume method (FVM) with moving boundary condition. In comparison with the theoretical approximation and experimental results, it was found that some difference occurrs in the case of the lower aspect ratio of the piston. However, when aspect ratio is large and piston speed is low, the theoretical approximation and experimental results show fair agreement. On the contrary the simulation results showed a good agreement with whole results in experiments.