Influence of Mass Distribution on Samara Descent Motions.*

Samaras are fruits with heavier seeds and lighter flat wings, which influence their dispersal approaches and play a key role in plant reproduction. This study presents a framework to alter mass distribution on a plate to present the diverse patterns of samara descent. We found that changing the mass distribution results in five distinct flight modes. Statistical analysis suggests that periodic descent patterns like autorotation and spiral tumbling are prevalent in nature, likely due to their stable flight performance. Further simulations reveal that vortices and wake interactions are crucial for lift production and maintaining flight modes. These results demonstrate how strategic mass distribution in samaras enhances their spread and provide new ideas for designing biomimetic flying devices.