Vortex ring dynamics may open new window into heart health

The dynamics of vortex rings (VRs), fundamental flow structures common in both natural and engineered systems, are largely determined by their immediate surroundings. Many studies have focused on the effects of confinement and asymmetry on VR dynamics independently, but few have concentrated on their effects simultaneously, which better contextualizes many real-life flow scenarios, including blood circulation in the heart.

Yin et al. explored this relatively understudied terrain by characterizing the three-dimensional evolution of VR structures and examining kinematic features like circulation, induced velocity, and vortex trajectory in simulations. They developed a scaling model to quantify their results.

“Our study investigates the fundamental fluid dynamics problem of how a VR behaves … in a confined and asymmetric region,” said author Yang Xiang. “We found that when a VR is launched asymmetrically (closer to one wall than another), it does not simply travel in a straight line or immediately dissipate but instead undergoes a distinct, three-stage evolution.”

Of the three stages — symmetric growth, asymmetric inclination, and reorientation – the third represents a critical discovery: The VR spontaneously corrects its trajectory, steering itself back toward the center of the channel axis. The implications extend beyond fundamental fluid physics, given the left ventricle of the human heart is an asymmetric receptacle for blood flow.

“Our findings suggest this biological asymmetry is not an imperfection but an optimized design,” said Xiang. “The heart may leverage these specific flow dynamics — tilting and reorienting — to efficiently redirect blood toward the aorta for ejection.”

The researchers hope their work may help introduce ways to recognize deviations from healthy asymmetric vortex behavior that signal cardiac anomalies.

Source: “Evolution and dynamics of vortex rings in a confined and asymmetric region,” by Yufei Yin, Lunbing Chen, Liwei Hu, Yang Xiang, Yumin Zhong, and Hong Liu, Physics of Fluids (2025). The article can be accessed at: https://doi.org/10.1063/5.0304637 .