## 3 Results and Discussion
### Simulation Results  
#### 3.3.1 Airflow Characteristics  
When multiple small jets from several adjacent air inlets flowed along the jet direction and reached a specific distance, the small jets merged into one large jet. The distance between the merge point of the jets and the air inlet was determined by the spacing between the adjacent air inlets. Air inlets with small spacing were prone to cause a negative pressure zone in the central area, which accelerated the merging of the edge jet to the central jet. The interaction between the air jets directly affected the indoor environment; thus, three typical air inlet spacings from the numerical simulation results were selected for comprehensive analysis. Figure 10 shows the sectional velocity distribution contours for x = 1.5 m, 1.7 m, and 1.9 m with supply air inlet spacings of 500 mm, 950 mm, and 1100 mm, respectively. Three parallel jets at L = 500 mm began to overlap, affecting the air distribution in the occupied zone at x = 1.5 m. The velocity distribution contour clearly shows the peak velocity in the overlapping area; the velocity of the three parallel jets tends to decrease with an increase in the distance between the jet body and the air inlet. However, there was no obvious overlap between the 950 mm and 1100 mm spacings. The supply air formed three independent air jets as the distance increased and started to overlap in the lower half of the axial plane instead of forming a confluence in the horizontal planes of the air inlets. Previous studies [34; 53] have shown that the velocity profile exhibits a strong asymmetry  
Figure 9: Lines 1-4 of four experimental cases at 1.1 m above floor: **(a)** air temperature; **(b)** air velocity. of its center downstream of the horizontal non-isothermal jet, mainly caused by the strong mixing of the lower part of the jet. The upper part formed a stable temperature and velocity layer; the lower part did not. Thus, the merging of the lower part of multiple parallel non-isothermal jets became stronger with an increase in the distance between the jet body and the air inlet. Figures 11 and 12 show the velocity distribution contour and temperature distribution contour in the plane z = 1.1 m at different air inlet spacings, respectively. Most of the main bodies of the jet with a 500 mm supply air inlet spacing overlapped each other to form a concentrated jet coverage area with a high air velocity. However, there was an obvious area with inadequate airflow on both sides of the occupied zone, where occupants may feel too warm. In addition, there were two large eddy regions on both sides of the rear of the room. The overlapping area of the jet gradually decreased with increasing supply air inlet spacing, which also increased the horizontal coverage area. The airflow on both sides of the occupied zone became stronger, and the air velocity in front of the second row of personnel was more uniform. In addition, the eddy regions at the rear of the room were also improved. When the supply air inlet spacing was increased to 950 mm, the overlapping area of the three jets in front of the first row of personnel also gradually decreased, and an area that could not be completely covered appeared between the jets. Insufficient airflow directly affects the thermal environment of an area. As the air inlet spacing increased to 1250 mm, the three jets were almost sent into the occupied zone in isolation with no confluence. The airflow in some areas between the jets was insufficient, and some areas between jets were almost unaffected by the jets. Additionally, the air inlets on both sides faced the first row of occupants. Although the jets were isolated before reaching the first row of occupants, the range of the jets widened owing to the blocking effect of the occupants. The thermal environment of the area that could not be fully covered between the jets can also be improved. Moreover, the eddy flows appeared on both sides of the room near the air inlets.