Wind-tunnel studies of effects of construction methods, design details, and canopy slots on the aerodynamic characteristics of small-scale all-flexible parawings

Includes bibliographical references (p. 18).

A low- speed wind-tunnel investigation was conducted to determine the effects of canopy construction methods, design details, and canopy slots on the static longitudinal aerodynamic characteristics of all-flexible parawings. Construction details such as type of nonporous canopy fabric, glued or sewed seams, tape reinforcement, or cloth-weave orientation had little effect on maximum lift-drag ratios and resultant-force coefficients. The maximum lift-drag ratios varied from 2.2 to 2.5 for the various single-keel unslotted parawings, and from 2.2 to 2.4 for the slotted canopy parawings. Incremental reductions in the lengths of all the suspension lines caused corresponding reductions in the resultantforce coefficients and maximum lift-drag ratios. The available range for modulation of resultant-force coefficient and lift-drag ratio by shortening the control lines was very limited.