The Local Motions of a Payload Supported by a Tritethered Natural Shape Balloon.
AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS
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The report compares the payload motions during flights of a 793 cubic meter 28,000 cubic feet natural-shape balloon on a tritethered cable array with those using an identical balloon on a single cable. Nominal altitudes were 457 m 1500 ft, 610 m 2000 ft, and 762 m 2500 ft above ground level at Holloman AFB and White Sands Missile Range, New Mexico. Winds ranged from 0.5 msec to 12 msec 1 to 23 knots. The payload location relative to the balloon was varied and the balloon was flown with different values of free lift and elevation angles. Target position, tangential speed, and acceleration were determined by using the WSMR cinetheodolite system. Telemetry included pitch and roll gyros, a flux-gate compass, accelerometers, and an anemometer. With both types of cable arrangement, one component of the motion was an oscillation similar in order of magnitude of frequency and orientation to the classic transverse oscillations of a sphere due to periodic vortex shedding in its wake. Author
- Lighter-than-air Aircraft