Drag Coefficients for Partially Inflated Flat Circular Parachutes

Free-body tests were made in the Langley spin tunnel to determine drag coefficients for 1.07-meter-diameter (3.5-foot) flat circular parachutes when restrained by wire frames in a series of shapes representing those that parachutes assume during the inflation process. Both high-porosity (stable) and low-porosity (unstable) parachutes were investigated. The results obtained should be applicable to inflation analyses for flat circular parachutes.