In this study, thermal comfort was simulated through flow analysis and the air conditioner vent location inside a tractor cabin was determined. The heating test of a tractor in an environmental chamber was performed to obtain temperature data at thermal equilibrium, and this result was used as the boundary condition for the simulation. The properties of the cold air input through the air conditioner vent were obtained through a cooling performance test. The inside of the tractor cabin was modeled, and a grid was created to perform the flow analysis. Predicted mean vote (PMV) and predicted percentage of dissatisfied were used to evaluate thermal comfort, and the temperature, air velocity, and humidity for calculating PMV were simulated. The temperature and PMV measurement locations were based on the temperature measurement positions proposed in SAE J1503.
The locations of the air conditioner vent selected as the simulation target were the ceiling, dashboard, and side column. These locations were selected based on the actual location of the air conditioner vent in the tractor cabin. The flow field with the lowest kinetic energy loss was formed when the air conditioner vent was positioned on the dashboard. In this case, the average temperature was 22.2 °C, which was 3 °C lower than that at other locations. In addition, the average PMV was 0.53, which was 1 lower than that at other locations. Based on the results of this analysis, it was found that the most comfortable environment of the tractor cabin was created when the air conditioner vent was located on the dashboard.
This study is the first to evaluate the thermal comfort of agricultural tractors using simulation. The simulated temperature showed a deviation of 2 °C or less from the measured temperature. This confirms that the simulation model can ensure accuracy. These results show the possibility that simulation can be used for studying thermal comfort.