Flat circular parachute with lateral mobility

Parachutes provide rapid vertical deceleration, but are more useful if they also provide stable, controllable lateral movement. A simple, effective method for lateral motion is to cut asymmetrical slits or holes in the canopy. This study simulated flat circular parachute designs with asymmetric holes and slits. The flow fields and the drag and lateral force coefficients of several designs were compared to determine how effectively these parachutes provide lateral motion. The parachute with a 30° annular slit starting from the bottom of the canopy provides the best drag. Further design variations shortened the length of the annular seam and gradually added radial holes. In all the designs, the U-shaped slit greatly improves both the drag and the lateral motion of the parachute and gives the best stability with changes in the angle of attack.