STATUS OF MSBS STUDY AT NAL

SUMMARYTwo magnetic Suspension and Balance Systems (MSBS) at the NationalAerospace Laboratory (NAL) in Ja--pan are introduced. They are l--0cm MSBSand 60cm MSBS. They have 10cm x 10cm and 60cm x 60cm test sections.The control of suspending a model at the 10cm MSBS is the 6 degrees offreedom including the rolling moment control. The model for the roll-ing moment control has two pairs of small extra permanent magnets atboth its ends plus a main cylindrical magnet. The rolling moment isgenerated by the magnetic forces acting on the extra magnets by con-trolled current passing through the four side coils independently.Test results show the roll angle of the model is controlled in thisway. The dynamic calibration test was carried out at the MSBS in 5degree of freedom without the rolling moment control. The model is asimple cylindrical magnet magnetized along its axis. The obtainedresults show that the dynamic calibration with measured magnetic fieldintensity is much superior to that with the coil currents. The 60cmMSBS was designed with some data obtained at the 10cm one. It isfundamentally proportional to the 10cm one in size and coils position.The measured magnetic field intensity is not so strong as expected atdesign. It was operated first in 1993. The control is 3 degree offreedom in the longitudinal direction. The size of it is the largestone in the world presently.INTRODUCTIONThe MSBS is a very attractive instrument of the wind tunnel test-ing technologies because it can provide the support interferencefree test data and so on. However, only several MSBS's have beenoperated in the wind tunnel tests in some countries (ref. I). Themaximum one was the 40 cm x 60 cm in its test section at Russia (ref.2). Primitive study was started at NAL about 8 years ago to build apractical sized MSBS in the future. The 10cm MSBS was built in 1985 andwas operated first in 1987 (ref. 3). It has been improved in manypoints since that time. The purposes of the 10cm MSBS were to examinethe way of designing it and to get a way of designing a larger one andto gain experience in operating it. Some fundamental data relating toP._GE BLANK NOT F'tLM__D275https://ntrs.nasa.gov/search.jsp?R=19940031347 2020-05-06T08:49:47+00:00Z