Doctoral Dissertations
Date of Award
12-2025
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Major
Mechanical Engineering
Major Professor
Andrew Dickerson
Committee Members
Andrew Dickerson, Wei Wang, Tadd Truscott, Sunghwan Jung
Abstract
Samaras, the winged seeds of trees such as maple, ash, and poplar, utilize passive aerodynamic mechanisms for wind-driven dispersal. While maple samaras are well-documented for their stable autorotation, rolling samaras, including those from ash and poplar species, exhibit a coupled rolling-autorotative motion that remains less understood. The aerodynamic mechanisms governing both maple and rolling samaras are characterized, with a particular focus on their response to morphological and dynamic perturbations. High-speed imaging, wind tunnel experiments, and computational modeling quantify the kinematics, aerodynamic stability, and recovery mechanisms of samaras under controlled conditions. The influence of mass distribution, wing morphology, and environmental perturbations—such as crosswinds and raindrop impacts—on dispersal efficiency is analyzed. Experimental results demonstrate that maple samaras maintain robust autorotation despite external disturbances, rapidly recovering from transient aerodynamic disruptions. In contrast, rolling samaras exhibit a more complex aerodynamic response, where rolling motion influences both stability and lateral displacement in turbulent environments. Bridging gaps in the understanding of natural dispersal mechanisms advances ecological studies of wind-dispersed seeds and informs bio-inspired flight applications, particularly in passive aerial vehicle design. Insights from this work contribute to improving seed dispersal models, optimizing conservation strategies, and inspiring innovations in bio-inspired robotics and micro-airborne systems.
Recommended Citation
Schaeffer, Breanna M., "Morphological and dynamic perturbations of autorotating samaras. " PhD diss., University of Tennessee, 2025.
https://trace.tennessee.edu/utk_graddiss/13638