*3.1. Vehicle Computational Model*

Figure 6 presents the vehicle model established referring to the original data of a hatchback, in which the engine and luggage compartment were ignored. In addition, some interior components including safety belts, electrical equipment and console details were neglected due to the fewer effects on airflow. The details of the dimension are shown in Table 3. The passenger compartment was designed with eight air conditioning inlets and two outlets. Four inlets are located on the center console. Among them, No.1 and No.2 are, respectively, located on the middle, facing the gap between the two bucket seats. No.3 and No.4 are located on the sides. No.5 and No.6 are, respectively, arranged in the feet space of the driver and passenger. No.7 and No.8 are located on the armrest box, facing the bench seat. The air outlets No.1 and No.2 are located on the rear board. No additional airflow inlet and outlet are included anymore under the well-sealed assumption. The vehicle computational domain was discretized using unstructured tetrahedron grids [55]. Inflation layers were used at the interfaces between the air volume and the solids. The case study adopted 3.8 million elements after converting the domain to the polyhedral meshes.



**Figure 6.** The computational model of the passenger compartment.
