Abstract
An experimental study was conducted of the performance of a translatory, magnetic suspension utilizing ceramic permanent magnets for vertical support and servo-controlled electromagnets for lateral stability. Drag measurements were confined to low velocities ([less than double sim] 40 cm/sec); a typical measured value of drag coefficient is drag force/weight = 1.8 × 10−4 at 18 cm/sec. Use of laminated electrical sheet rather than mild steel should provide an order of magnitude reduction in this value. For low amplitude oscillations in a magnetic valley, drag decreases further by about two orders of magnitude; free oscillations have been observed to continue for 12 min. In contrast, instrument quality ball bearings have a friction coefficient in the 10 to 40 × 10−4 range. The total power required to maintain support is about two orders of magnitude lower than for a dc electromagnet suspension system. Assuming eddy current drag force proportional to velocity and hysteretic drag force independent of velocity, measured drag values extrapolated to high speed indicate that with laminated magnetic elements, the magnetic drag force would be low compared to air drag for a similarly suspended vehicle traveling at 270 m/sec (600 mph) in a tube evacuated to 10−3 atm. The vehicle coasting at this velocity would lose little more than 1% of its velocity in 93 km (53 miles).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
