Status of MSBS Study at NAL in 1995

Magnetic field intensity and currents passing through the coils of the National Aerospace Laboratory (NU) 1Ocm Magnetic Suspension and Balance System (MSBS) were measured while a cylindrical model was oscillated along x,y,z and also about y and z axes, respectively. The model was made of alnico 5 and was 8inm in diameter and 6hm long. Two kinds of tests were carried out. Amplitude of the oscillation was varied at a frequency of 10Hz. Frequency was varied from 1 to 50Hz in the other test. Results of the tests show that the relation between coil currents and magnetic force acting on the model is affected by frequency. They also show that the relation between measured magnetic field intensity and the force in vertical direction is independent of the frequency below 30Hz. Using the measured magnetic field intensity, the vertical force can be evaluated at the MSBS instantaneously when a model moves at frequencies below 30Hz. A static drag force calibration test was carried out at the 60cm MSBS. Obtained relationships between measured drag coil currents and loads shows large hysteresis.