Airflow Organization Characteristics of Metro Train Passenger Compartment

［Objective］ The comfort of airflow delivery in metro air-conditioning systems is a critical indicator for the performance measurement. To ensure passenger comfort, it is necessary to maintain the indoor temperature and air velocity within a reasonable range in the passenger compartments. Therefore, an in-depth study of the airflow organiztion inside metro train compartments is essential. ［Method］ Focusing on the passenger compartment of a Tc car (trailer car with driver′s cabin) in a specific metro train, a comprehensive analysis of vehicle parameters and operating environment is conducted, followed by optimization of the air duct structure. On this basis, a geometric model is constructed and meshed. Using computational fluid dynamics (CFD) methods and simulation tools such as HyperMesh and STAR-CCM+, the airflow organization and temperature characteristics in the compartment are simulated under both no-load and full-load conditions. Experimental tests are carried out to validate and compare the simulation results. ［Result & Conclusion］ Under all operating conditions, the main airflow velocity within the compartment remains below 0.5 m/s, avoiding significant draft discomfort for passengers. However, issues of airflow short-circuiting and counterflow are still observed. In un-load condition, the compartment exhibits good uniformity in airflow organization and temperature distribution, while in full-load condition, the temperature distribution uniformity declines. The optimized air duct structure demonstrates excellent airflow delivery performance.