Experimental Investigation of Air Cushion Flutter Using a Two- Dimensional Trunk Model.

摘要

This program was an in-house project, to test the effectiveness of flutter control elements on an air cushion trunk. A single inelastic trunk carcass was used throughout the program. Individual elements were added to change the stiffness or mass of the fabric, or to control air flow under the trunk. The elements were tested individually and together. None of the elements was permanently attached to the trunk: rubber cement and duct tape were used to secure them. The motions of the trunk were observed under a variety of pressure and ground clearance settings. Manual data collections were made. Although the fabric used here was lighter than that used on the full-scale XC-8A aircraft tests, the performance of this quarter-scale rig was similar to what was seen on the actual aircraft. These passive elements did affect the amount of control force required to stop the large amplitude heave oscillations. Based on these tests, recommendations were made to produce a light, effective trunk system free of flutter.