Weinmann, Michelle | Search NASA

NASA NTRS2018

Further Development of an Electromagnetic Position Sensor for a Wind Tunnel MSBS

An Electromagnetic Position Sensor (EPS) was successfully developed in the 1960’s for the MIT “6-inch” Magnetic Suspension and Balance System. An updated version remains in use today, based on analog electronics. This paper will review the hardware revisions made to successfully adapt the system for use in sensing 3 degrees-of-freedom motion of small spherical or near-spherical suspended models. Practical challenges related to electrical noise sensitivity and stray coupling paths will be discussed. Preliminary analysis of alternative demodulation approaches, including digital signal processing, will be reviewed.

Britcher, Colin↗

NASA NTRS2018

Preliminary Aerodynamic Measurements from a Magnetic Suspension and Balance System in a Low-Speed Wind Tunnel

An existing Magnetic Suspension and Balance System (MSBS) has been restored to operation in a small (octagonal test section, 6-inches across flats) low-speed wind tunnel as the first phase of a project to develop new dynamic test capabilities for planetary entry capsules at supersonic speeds. The MSBS and associated wind tunnel were originally designed and built at MIT and were subsequently relocated to NASA Langley Research Center. NASA ceased operations of the system in the late 1990s and it was transferred to Old Dominion University where it had been mothballed until the present work started in 2015. All-new position sensor electronics, electromagnet power supplies, digital controller, and other hardware have been developed, leading to more efficient and reliable operation. Important features of the new hardware will be briefly described. Wind tunnel testing has commenced, focusing first on static aerodynamics of re-entry capsule shapes. Some preliminary results will be reviewed, including comparison to reference data. The proposed extension to dynamic stability testing, using a variety of free-to-pitch approaches will be described. Finally, the preliminary design of the all-new Phase II (supersonic) system will be briefly outlined.

Schoenenberger, Mark↗