Design and Implementation of a Launching Method for Free to Oscillate Dynamic Stability Testing

Magnetic Suspension and Balance Systems (MSBS) allow for static, forced oscillation and free to oscillate dynamic stability testing in a wind tunnel without the need for a physical support. The objectives of study are to assist in the application of the free to oscillate testing method in an MSBS to determine dynamic stability characteristics for various re-entry capsule designs. This thesis discusses the development and testing of a launching method called the grabber for use in the MSBS Subsonic Wind Tunnel at NASA Langley Research Center. Aerodynamic tests were run to support the use of this method and compare the data gathered to data taken from previous runs with other supports. Aerodynamic testing showed that the implementation of the designed launching method yielded less axial and vertical interference overall by the newly designed launcher as opposed to previous launching approaches, with the designed launching method having a maximum axial movement of 4.11 mm and a maximum vertical movement of 5.075 mm, and the other supports having displacements of more than twice that. While the outcome was successful, possible improvements and streamlined designs were identified and preliminarily developed for use in a future supersonic MSBS facility. A simulation was created to visualize the behavior of a model released into the windstream unsuspended for both subsonic and supersonic conditions. This data was mapped against the results from the launcher’s retraction to show the estimated path the model would follow. These results indicate the feasibility of this launching method in the proposed supersonic facility