Learning how to fly from dandelion seeds

The unique parachute-like seeds of dandelions are able to travel long distances in even just a slight breeze. Understanding how they travel could help design future aerial vehicles.

Qin et al. simulated dandelion seed flight to better understand their unique locomotion. Focusing on the pappus, the delicate, feather-like structures that buoy the seed in the wind, the researchers’ simplified model includes long, slender, radially-arranged filaments. They then used computational fluid dynamics calculations to study the airflow around the seed, as well as the crosswinds that commonly drive dandelion flight.

“We investigated the influence of the combined effect of crosswinds and vertical winds on the dandelion’s airflow,” said author Lifeng Ma. “The simulation results show that the dandelion seed is able to self-adapt its attitude to keep its flying stable.”

The results showed the torque on the pappus increases with the folding angle, the angle between the dandelion’s filament and the pappus. However, the drag coefficient decreased as the folding angle increased. A seed with a folding angle between 20 to 40 degrees offered a good balance between stability and drag.

“We believe these findings can be applied to the design of biomimetic micro aerial vehicles, including dandelion-inspired ones,” Ma said. “For example, the knowledge we’ve gained about the folding angle intervals could be especially useful in designing more efficient designs.”

Next, the researchers plan to investigate deformations to the pappus caused by the wind to investigate the impact of flexible filaments on airflow.

Source: “On the attitude stability of flying dandelion seeds,” by Lang Qin, Zhen Jian, Yeyin Xu, and Lifeng Ma, Physics of Fluids (2023). The article can be accessed at https://doi.org/10.1063/5.0160735 .