Investigation and CFD Optimization of Wind Environment in Large-Scale Gymnasiums Located in Cold Regions

Large-scale gymnasium buildings are characterized by spacious interiors and high occupant density, requiring a design that balances spectator comfort and health standards while achieving precise control of wind speed, humidity, and temperature in the competition area. This study focuses on a large university gymnasium in Xi’an, using the CFD software PHOENICS to simulate its indoor wind environment under typical summer conditions. The analysis examines temperature, wind speed, and air age variations across temporal (6:00–18:00) and spatial (different architectural forms) scales. Results indicate that high-set ventilation windows lead to poor ventilation, with wind speeds below 1 m/s, temperatures exceeding 34°C, and air age over 300 s at 1.5 m height. Simulations show that increasing window openings and optimizing their placement improve ventilation efficiency. Square gymnasiums exhibit higher wind speeds but elevated temperature and air age, while circular ones have the highest air age. Recommendations include adding low-level ventilation windows, mechanical ventilation in weak areas, optimizing window-to-wall ratios, and refining roof forms to enhance natural ventilation, offering theoretical and technical insights for low-energy designs of large-space buildings in cold regions.