Effect of ventilation on airflow pattern and thermal environment inside tractor cabin in summer: A case study of numerical simulation

As the tractor plays a more and more important role in agricultural operation, it is very important and meaningful to study the thermal environment in its cabin to improve the thermal comfort of the operator. In this study, the heat transfer model in the tractor cabin is established by using computational fluid dynamics (CFD), and the effectiveness of the numerical model is verified by field measurement. The distribution of airflow, temperature and the equilibrium temperature of cabin under different ventilation conditions are deeply discussed. The thermal comfort of driver was evaluated by predicted mean vote (PMV), predicted percentage of dissatisfied (PPD) and asymmetry coefficient. The simulation results show that the cooling effect and speed of the cabin are more stable by reducing the air supply temperature, and in a certain range of low air supply speed, increasing the air supply speed is more effective for cabin cooling. Considering the cooling rate, cooling effect and human thermal comfort, the combination of air supply temperature of 16 & DEG;C, air supply speed of 1.0 m s(-1) and vertical guide vane angle of 60 & DEG; can be considered as the appropriate conditions for summer cooling. Additionally, on the basis of the same energy consumption, thermal comfort can be improved by increasing the air supply speed for refrigeration. This study provides a theoretical basis for the adjustment of the ventilation condition from different perspectives such as the cooling effect and human thermal comfort.