Development of a Methodology to Calculate the Projected Area of a Freefall Skydiver and a Comparative Study Based on Anthropometry

For skydivers and special forces performing military free-fall operations, they move toward the drop zone in a variety of positions, including Cross, Box/Frog, and Delta, before deploying their parachute. As the human body moves, various aerodynamic characteristics change, such as the speed and direction of movement, the rate of descent, and the rotation of the posture, and the most important parameter to find the forces and moments acting on the human body is the projected area of the human body. In the past, anthropometric research methods were used to determine the cross-sectional area according to the body type of the diver, but recently, methods such as constructing a three-dimensional human body model through anthropometric measurements and obtaining the cross-sectional area by numerical analysis using Catia, Photoshop Extended, and MATLAB are being used. However, the method of constructing parametric equations based on anthropometry is highly utilized in skydiving or parachute training simulators because it is easier to calculate by knowing only a few anthropometric parameters compared to modern calculation tools. While previous studies have utilized statistical approaches and tools to find such parametric equations, this study uses an AI approach to identify key parameters and find a parametric equation of minimized order consisting of extracted parameters. This research can be extended in the future by finding parametric equations that can be applied to various skydiver’s positions, and it is expected that this approach can be applied to various flight styles of the human body, such as flying with a wingsuit.