Oak Ridge Flywheel Evaluation Laboratory Test Report on the Garrett AiResearch Flywheel

摘要

The high-energy-density Flywheel G-1, bulit by Garrett AiResearch Manufacturing Company, was tested with only minor deviations from the test plan. Dimensional measurements were made within two weeks after receiving the part and were repeated after Run 9. The graphite-epoxy-composite spokes began to splinter in four tip locations after the sixth balance run to 200 Hz (12,000 rpm). Testing was continued until a catastrophic failure was achieved. The spoke splintering did not appear to be a factor in the ultimate capability. Maximum stored energy was 1.16 kWh (4.17 MJ) at 74.6 Wh/kg (269 kJ/kg) at 463 rps (27,780 rpm). Ultimate speed was limited by a dynamic instability at 463 rps. Actual failure occurred in a braking mode at 390 rps. Other observations of dynamic behavior included the mass eccentricity shifting repeatably with speed at a rate of 0.051 mm in 170 Hz; this action was attributed to nonuniform flexing of the rim. A permanent balance shift of approximately 0.051 mm occurred, possibly indicating a slippage of the rim relative to the hub. Radiography shows that the rims realigned themselves. Finally, the channels in the hub proved very difficult to outgas and required extremely long pump-down times to achieve the specified 10- exp 3 -torr chamber pressure. (ERA citation 06:018707)