Advanced Magnetic Suspension and Balance System Having Characteristics of Light Weight, Electric Power Saving, and Fast Response

We have developed an advanced magnetic suspension and balance system (MSBS), in which iron yokes are not used and a pair of strong magnets are installed to generate magnetic force compensating gravitational force applied to the aerodynamic models. By the introduction of these strong magnets, the electric power saving was realized. By not using iron yokes, not only the weight saving was realized but also the electrical response speed was increased due to the reduction of the inductance of the magnetic coils. The test section of the MSBS is 36 cm × 40 cm. We have developed the control method to support the model and give an arbitral movement of small amplitude at the center of the test section around five axes. In order to evaluate the characteristics of this MSBS, we performed the calibration tests of magnetic forces for our MSBS. We measured drag coefficients of a sphere aerodynamic model in order to confirm the performance of these MSBSs and had good agreements between the measured values and the values appeared in the common aerodynamic hand book. The MSBS has been studied and used in large scale laboratories. We think that these experimental results make the application of the MSBS into the wind tunnel experiment easier and can be the trigger to popularize it in small laboratories.