Recently, a research team led by Professor Hong Liu and Associate Professor Yang Xiang from the School of Aeronautics and Astronautics at Shanghai Jiao Tong University, in close collaboration with the Shanghai Children's Medical Center, published a paper titled "Evolution and Dynamics of Vortex Rings in A Confined and Asymmetric Region." This research was featured in an exclusive interview by Scilight, a publication of the American Institute of Physics (AIP), and was published as an Editor's Pick in the AIP journal Physics of Fluids.

    Vortex rings are fundamental flow structures ubiquitous in nature and engineering systems. Their formation and evolution critically impact the transport of momentum, energy, and mass. While previous studies have independently revealed the mechanisms by which confined boundaries or geometric asymmetry affect vortex ring dynamics, these two factors often coexist in real-world systems. However, there remains a lack of understanding regarding their coupled effects and dominant mechanisms.

    By conducting high-resolution numerical simulations on the evolution of vortex rings in three-dimensional asymmetric confined spaces, this study discovered a typical evolutionary path in such environments: symmetric growth, asymmetric tilting, and global redirection. The findings indicate that geometric asymmetry does not simply disrupt the structural stability of the vortex ring. Instead, it modulates the wall-induced velocity field and vorticity distribution, triggering a redistribution of the vortex ring's momentum and thereby driving an adaptive adjustment of its spatial orientation.Building upon this, the authors established a scaling model to quantitatively characterize the key dynamical features of the vortex ring's tilting angle and redirection process. This provides a theoretical basis for predicting vortex ring behaviors under various confinement and asymmetry parameters. These results offer a novel physical perspective for understanding complex biological flows, such as the organization and guidance of blood jets within ventricles. They suggest that the asymmetric geometric structure of the ventricle may not be an impediment to flow, but rather a functional design that facilitates efficient blood ejection.

    Professors Hong Liu and Yang Xiang are the corresponding authors of this study, and Yufei Yin, a master's student in the team, is the first author. The project was supported by the National Natural Science Foundation of China and the Explorer Program of the Science and Technology Commission of Shanghai Municipality. The team's research interests encompass drag reduction for large aircraft, vortex dynamics, biofluids, artificial intelligence, and aircraft design.

    Founded in June 2017, Scilight is a weekly online publication by AIP Publishing. It is dedicated to highlighting the latest and most representative articles published by AIP in the physical sciences by briefly summarizing the research findings and emphasizing their innovation and breakthroughs. Each year, Scilight selects and features only about 300 of the most noteworthy research achievements from over 30 journals under the AIP umbrella.

▶ Physics of Fluids Paper Link

https://doi.org/10.1063/5.0304637

▶ AIP Scilight Feature Article Link

https://doi.org/10.1063/10.0042202