Study on powered-parafoil longitudinal flight performance with a fast estimation model

Parafoils have more applications than traditional parachutes because of their better glide ratio and maneuverability. They are used, not only as travel carriers in sports and tourism, but also as precision aerial-delivery tools for military paratroopers and supplies. Furthermore, powered parafoils with the ability to take off from the ground and to cruise for a long time extend the possible applications. A simple static model, which is more convenient for fast estimation or optimization design, was established in this paper. To explain the canopy collapse which happened in a powered parafoil test flight, the state parameters were solved at different thrust levels with the considering of the relative rotation between the canopy and the payload. The parafoil was launched using manpower in test flights. It can be observed that, during several flights, the parafoil climbs steadily after takeoff with the appropriate power. The climbing angle increases with the increase of thrust until a critical value is reached, which causes the collapse of the canopy.