Comparison of Support Methods for Static Aerodynamic Testing and Validation of a Magnetic Suspension and Balance System

Abstract

COMPARISON OF SUPPORT METHODS FOR STATIC AERODYNAMIC TESTING AND VALIDATION OF MAGNETIC SUSPENSION AND BALANCE SYSTEM Cameron K. Neill Old Dominion University, 2019 Director: Dr. Colin Britcher Magnetic suspension wind tunnels offer an alternative to traditional physical support methods. They allow for the collection of support interference free data and broader dynamic test capabilities than existing methods. Determination of dynamic aerodynamic characteristics is a crucial portion of the design of new re-entry capsules. A NASA initiative restored the 6-inch Magnetic Suspension and Balance System to support the design of a new MSBS for a supersonic wind tunnel. Before a new MSBS can be constructed, the characteristics of the current MSBS must be examined. This thesis discusses the calibration and validation of the 6-inch MSBS. After calibration, three aerodynamic tests were performed in order to characterize the data collected from the MSBS. They included a traditional sting supported test, a free-flying magnetically suspended test, and a magnetically suspended test with aerodynamic interference from a dummy sting. The ideology behind the chosen experimental design was to isolate the effect of support interference from any MSBS calibration errors. Any differences between the sting supported and the dummy sting tests would be caused by the MSBS. Any differences between the free-flying and the dummy sting tests would be due to support interference. Multiple components were designed and constructed, in order to support this effort. The goals of this thesis were met. The MSBS data had high repeatability and accuracy, which validated the force recovery method. Aerodynamic testing showed in minimal variation between support methods at low angles of attack. Discrepancies between support methods increased with models mounted at high angles of attack. Current references generally exhibit much higher Reynolds numbers than the MSBS and the wind tunnel can achieve. Support interference free reference data in an achievable Reynolds number was generated for future NASA testing. While the outcome was successful, multiple possible improvements or future projects were identified that can be completed prior to design and construction of the new MSBS.