Large eddy simulation-based modeling of cold-air inhalation from nasal cavities to the distal lung : insights for athlete health and performance

In cold environments, athletes are frequently susceptible to injuries from inhaling cold and dry air, posing significant health risks. Despite abundant prior research focusing on risk analysis and prevention, the existing body of literature has predominantly focused on heat transfer within lung airways while mainly overlooking the broader respiratory tract. This pioneering study introduces a comprehensive assessment of the entire respiratory system, spanning from the nasal and oral cavities to the larynx, then the trachea, and extending to the 13th generation of lung airways. Employing cutting-edge Computational Fluid Dynamics (CFD) techniques, the investigation operates Large Eddy Simulation (LES) integrated with an algebraic wall-modeled LES subgrid-scale model to simulate heat transfer within the human lung. This approach provides a detailed insight into the complex dynamics of respiratory thermoregulation in cold environments. By offering a comprehensive analysis of the temperature, heat flux, Nusselt number and static pressure profiles throughout the respiratory system, this study fundamentally advances our understanding of the physiological responses of the respiratory system to cold air exposure. These findings have paramount implications for athlete health and performance, shedding light on the complexities of cold-induced respiratory challenges. Moreover, this research lays a solid foundation for developing more effective preventive measures and strategies for optimizing athletic performance in cold weather conditions.