M. Motozawa Y. Kato W. Rakpakdee M. Fukuta


Sealing performance and flow characteristics of magnetic fluid in extremely tiny clearance less than 10 μm under magnetic field are investigated experimentally. The clearance in the test section is set to 15, 20, 30 and 50 μm in addition to the extremely tiny clearances of 5 and 10 μm, and magnetic field is applied to magnetic fluid flow at the clearance. The results show that 1.2 MPa of maximum pressure resistance was obtained at 5 μm of extremely tiny clearance from the pressure resistance test for high viscosity magnetic fluid, and the relationship among frictional coefficient, magnetic field and Re is quite different among 5, 20 and 50 μm of tiny clearance from the flow characteristic test.