Characteristic of short-range exposure to cough-produced vortex rings under different mouth shapes and velocities using large eddy simulationKaijun Li, Ruibin Li, Lingjun Xiao, Naiping Gao and Yan WuE3S Web Conf., 689 (2026) 06006DOI: https://doi.org/10.1051/e3sconf/202668906006