Meeting Abstract

43.2  Thursday, Jan. 5  Inertial and Fluid Forces during Bat Flight Maneuvers BERGOU, AJ*; FRANCK, J; REIMNITZ, L; RISKIN, D; TAUBIN, G; SWARTZ, S; BREUER, K; Brown University attila_bergou@brown.edu

Flying animals generate forces and torques to move through the air by coordinating the movement of their wings. Bats have evolved a particularly impressive capacity for flight control: with a very large number of wing joints, bats are able to extensively manipulate wing shape. By changing wing area, angle of attack, and camber, bat are able to control their flight through altering aerodynamic forces on their wings. The relative heaviness of bat wings compared to their total body mass, opens a second mode of control for these animals:  by changing wing shape, bats are also able to control their flight through altering their overall mass distribution - generating apparent "inertial forces". Here, we use a model-based tracking framework to reconstruct detailed wing and body kinematics of maneuvering bats from high-speed video. Using this data, we extract simplified wing geometry and kinematics to estimate the aerodynamic forces on a bat's wings with numerical simulations. We use these forces with a low-order dynamical model of a bat to reconstruct how bats can adjust their wing motion to generate various flight maneuvers. Our reconstruction highlights the importance of both inertial and aerodynamic forces for flight control by bats.