Thread by @prnvkhndlwl

We show that wild #flyinglizards change their body posture and wing (airfoil) shape to use an #aerodynamic strategy that maximizes their glide distance while allowing them to modulate the lift and drag production in-flight. Why is this cool? (1/8)
nature.com/articles/s4159…

We constructed a seven-camera motion capture system in the Agumbe rainforest to record voluntary glides and measure (in detail) the kinematics and changes in body shape and posture of the #flyinglizard (no more than a palms length) gliding a distance of 5.5 m. (2/8)

#flyinglizards continuously changed their body orientation to hold a steady airfoil angle with respect to the oncoming wind (angle of attack, AoA); The steady AoA corresponded to their near-maximal lift-to-drag ratio which is desirable to maximize the glide distance. (3/8)

Along with fixed AoA, lizards also varied their airfoil camber, influencing lift and drag, and providing an additional mechanism to control aerodynamic forces. Together, fixed AoA and changing camber enable robust flight characteristics to changing environmental conditions. (4/8)

Compared to conventional static wind tunnel tests to measure airfoil performance (drag polar), our study captures the combined effect of changes in 3D airfoil shape (camber and dihedral angle) along with body posture on aerodynamic performance during the complete glide. (5/8)

More cool stuff: #flyinglizards achieved AoA > 55 deg without drastic loss in lift production (aerodynamic stall), showing the benefits of compliant biological airfoils! (6/8)

I am extremely proud of this study but none of it would have been possible without the help of 257 backers on the crowdfunding platform @lets_experiement and the tireless efforts of the entire team in the field and at @ARRS_India. Can't thank each one of them enough! (7/8)

Want to know more? For 'behind the scenes' of the study, do checkout the lab notes at
experiment.com/projects/how-t…
and
gadgets.ndtv.com/science/featur…
(8/8)