## 4 Conclusions  
In this study, a validated droplet evaporation and dispersion model was employed to numerically simulate the dispersion of respiratory pathogens carried within droplets in a three-dimensional cabin space defined by hanging curtains. The individual infection risks of nine passengers in a lounge were analyzed, with a particular focus on the impact of three variables: the arrangement of the hanging curtains, the sag height, and the overhang height, on the susceptibility of individuals to infection. Through our research, we found that hanging curtains as a physical isolation measure can significantly alter the airflow dynamics within a cabin space. Optimal and well-considered curtain configurations were shown to effectively inhibit the dispersion of droplets and particles. Hanging curtains between infected individuals and susceptible individuals in the front row, or partitioning the space based on passenger seating positions, were demonstrated to be preferable physical isolation strategies. The orthogonal test method showed that the optimal physical isolation  
Figure 12: Individual infection risk values regarding (**a**) the infected person positioned at CB (no curtains), (**b**) the infected person positioned at CB (optimal curtain solution), (**c**) the infected person positioned at AB (no curtains), and (**d**) the infected person positioned at AB (optimal curtain solution). strategy was achieved when the bottom coordinate of the curtain was at Z = 2.3 m and the top coordinate was at Z = 2.8 m. This configuration effectively confines and controls the dispersion of droplets. Furthermore, we verified the effectiveness of the obtained optimal arrangement. By changing the location of the infectious agent, the curtain scheme could still significantly reduce the probability of surrounding passengers being infected with respiratory infectious diseases. These results indicate that the partition management of confined spaces through rational configuration and the use of curtains is universal for reducing the risk of infection of passengers in similar scenarios, such as businesses and hospitals. During routine operations, curtains can be kept rolled up or folded to maintain the aesthetics and functionality of the cabin. However, during respiratory disease outbreaks, they can swiftly unfurl to form an effective isolation barrier. Nevertheless, this measure is not without its drawbacks, requiring regular cleaning and maintenance. Therefore, future research could explore optimizing curtain design by integrating sensors and automatic control systems to monitor air quality, crowd density, and indoor environmental parameters. This would enable automated adjustments to curtain position and operation, fully leveraging the physical isolation capabilities of hanging curtains for disease prevention. Meanwhile, it is to be noted that the applicability and effectiveness of physical isolation measures are affected by the specific environment of the place, and they cannot completely replace the role of masks. When there is a major outbreak of respiratory infections, wearing a mask is the most effective way to reduce the spread of droplets during breathing and speaking. Nevertheless, for socializing places where masks are not normally worn while eating and drinking, the proposed physical isolation method is presented as a practical means to prevent cross-infection and to alert individuals to maintain an appropriate social distance. Although this article currently focuses primarily on a single study of hanging curtains, this is just a starting point in the exploration process. We look forward to further exploring the collaborative optimization of physical isolation strategies and ventilation systems in the future to better enhance overall epidemic prevention effectiveness. Conceptualization, M.C. and H.S. ; methodology, M.C. and B.K. ; validation, Y.L. ; investigation, Y.L. ; data curation, M.C. and C.S. ; writing--original draft preparation, M.C. ; writing--review and editing, B.K. and H.S. ; supervision, B.K. and H.S.