| In recent years, high speed passenger train has become the major transporter of people’s travel with the rapid development of railway industry in China. The people’s living standard has been improved greatly, which followed by higher requirements for vehicle comfort. The air quality in the train has great relationship with the comfort in the train. Therefore, it is very necessary to have a further study of the air distribution situation and the air quality in the train.This article starts with the research on a high-speed train carriages. Then, with the help of Gambit set up the Computational Fluid Dynamics simulation model. Using Fluent fluid analysis software to simulate the velocity field and temperature field in the train with different air distribution. The results show that the area round air-admitting and air-outlet flow faster. What is more, the temperature in the train is decreased. The air flow pattern, velocity field and temperature field is greatly influenced by the supply of the air temperature and velocity. The temperature of the side which exposed to the direct sunlight increase about 0.5 degrees Kelvin. The temperature in the carriages increase both 4 degrees Kelvin and 1.5 degrees Kelvin considering the humidity of the air and carbon dioxide in the air.Then we take the breathing of the passengers into consideration. The results show that relative humidity increase from 44% to 44%~52% considering the breathing of the passengers. When the supply of the velocity increase 1m/s, the average relative humidity decrease about 1.8%. The temperature in the carriages increase 1.5 degrees Kelvin considering the breathing of the passengers. The velocity on the section of head is about 0.2m/s. The mass fraction of carbon dioxide of the area that aside the aisle is 0.015% higher than the area aside the window. When the supply of the velocity increase 1m/s, the average mass fraction of carbon dioxide decrease about 0.01%.Finally, we get the DR of the blowing feeling index and the thermal comfort evaluation index-Predicted Mean Vote and Predicted Percent Dissatisfied by User-Defined Function in Fluent. We analyze the DR of the blowing feeling index and the thermal comfort in the carriage under different air velocity and temperature. Then we get the distribution regularity of human body thermal comfort under different air supply parameters. Studies have shown that the thermal comfort is better with higher velocity and lower temperature. What is more, the blowing feeling is very strong with higher velocity supply. The best air supply velocity and temperature is 4m/s and 290 K. Afterwards, using extension method to evaluate the air quality of the carriages. Studies shows that the air quality of the carriages is better, which is consistent with the results of the simulation. |
