The Oxford Magnetic Suspension and Balance System: a Brief History & Development Status

This paper traces the history of the Oxford Magnetic Suspension and Balance System, from its initial development in the 1960s through to current times. Developed in conjunction with the Oxford Low Density Tunnel, the balance has been a key instrument throughout its history for investigating aerodynamic forces at high Mach numbers, low density flows across the continuum, slip and transition regimes. An initial balance was developed as a 2-axis system with control over only lift and drag. Following its success, a second balance was designed to control lift, drag and additionally pitch. This enabled more complex geometries, such as a re-entry Aerobrake model and NASA’s X-43 hypersonic demonstrator to be investigated. The evolution of the electro-mechanical design of each balance and the associated model attitude detection systems are described in this paper. Operational issues encountered with the system and sample results from past studies are also presented and discussed. The paper concludes with an outlook to the future development and application of the magnetic suspension balance system within the Oxford Low Density Tunnel.