AERODYNAMIC DEPLOYABLE DECELERATOR PERFORMANCE-EVALUATION PROGRAM. PHASE 3
Final rept. Apr 1965-Jul 1967
GOODYEAR AEROSPACE CORP AKRON OH AVIONICS AND ELECTRONICS RESEARCH AND DEVELOPMENT DIV
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The Aerodynamic Deployable Decelerator Performance-Evaluation Program ADDPEP has aimed to advance the state of the art by developing the most effective analytical and empirical techniques for designing aerodynamic deployable decelerators and for evaluating these engineering techniques through wind-tunnel and free-flight tests. During the third and concluding phase of ADDPEP, two types of decelerators were investigated large reefed supersonic parachutes and small supersonic parachutes. The areas investigated by tests included analytical and engineering design methods, material capabilities, and fabrication techniques. Three large parachutes were built that had the same basic configuration hemisflo, 16-ft-diameter canopy, 10-percent extended skirt, 10-percent porosity. These parachutes were designed for 200,000-lb opening loads. Free-flight tests were performed at deployment Mach numbers of 2.22, 1. 20, and 2.70 at altitudes of 18,050, 9370, and 19,700 ft and at dynamic pressures of 3697, 1514, and 5155 psf, respectively. The tests confirmed the predicted drag area. However, reefing line loads were underestimated improved analytical methods are needed to predict this hoop-type load under dynamic conditions at the higher Mach numbers. Three small parachutes were built that had the same basic configuration, designated PARASONIC 4-ft-diameter, 5-percent total porosity. Wind-tunnel tests confirmed that this PARASONIC design, when constructed of materials that are compatible with the flight environments investigated, has better stability than a HYPERFLO design that was also investigated in both Phases I and III.
- Lighter-than-air Aircraft