ESL / EFL Quiz 122

The paraglider wing or canopy is usually what is known in aeronautical engineering as a ram air airfoil. Such wings comprise two layers of fabric that are connected to internal supporting material in such a way as to form a row of cells. By leaving most of the cells open only at the leading edge, incoming air keeps the wing inflated, thus maintaining its shape. When inflated, the wings cross section has the typical teardrop aerofoil shape. Modern paraglider wings are made of high performance non porous materials such as ripstop polyester or nylon fabric.In some modern paragliders from the 1990s onwards, especially higher performance wings, some of the cells of the leading edge are closed to form a cleaner aerodynamic profile. Holes in the internal ribs allow a free flow of air from the open cells to these closed cells to inflate them, and also to the wingtips, which are also closed.