Meeting Abstract

97.5  Saturday, Jan. 7  Measurement of the aerodynamic stability and control effectiveness of human skydivers during free fall and directed aerial descent EVANGELISTA, D.*; CARDONA, G.; RAY, N.; TSE, K.; WONG, D.; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley devangel@berkeley.edu

We examined the aerodynamic stability and control effectiveness of human skydivers during free fall using models in a wind tunnel, full-scale tests in an indoor skydiving vertical wind tunnel, and data collection during actual skydives. Maneuvers during flight at high angles of attack are important to understand and are relevant to the evolution of aerial behaviors in many taxa. Human free fall is an understudied and important point of comparison: humans use both inertial and aerodynamic mechanisms to accomplish maneuvers and direct their descent, they are the largest vertebrate known to perform aerial behaviors, they can be asked to perform specific test maneuvers, and they are large enough to carry a complete set of instrumentation. We find that maneuvers at skydiving speeds are dominated by aerodynamic torques (vice inertial, as in human gymnasts tumbling at low speed). Human use of limbs as aerodynamic surfaces is consistent with those of smaller animal skydivers. Stability varies depending on axis of motion and glide angle and stability shapes which behaviors are effective in accomplishing maneuvers. The wide suite of behaviors available to a large mammal with no obvious aerial adaptations, presented with an extreme aerodynamic challenge, reinforces the importance of a maneuvering perspective in comparative studies of flight biology.