## 3 Results and Discussion
On the X220, X245, X320, and X345 axis lines, this velocity under the lower vehicles is approximately 15 m/s at Y = 525 cm, while it reaches its highest value around Y = 515 cm, reaching approximately 15.5 m/s. The velocity distribution between UAVs is examined both horizontally in Figure 8 and vertically in Figure 4:0 It is observed that speeds reach up to 7 m/s at X270 to X295 near the propeller's axis and up to 4 m/s at the midpoint X282.5. The developing airflow converges towards the airflow on the propeller axes, approximately 2.5 m under the UAVs-swarm, around Y = 300 cm, reaching speeds ranging between 7 and 8 m per second. Furthermore, at Y = 0 cm, the velocity at the outer axes (X345-X220) is approximately 1 m/s lower compared to other lines. All of this illustrates the impact of close-range UAV swarm flights on velocity. Figure 10 illustrates the total pressure contours taken from the front and rear propeller planes, as well as the mid-plane of the UAVs. Figure 10a illustrates the contours taken from the rear plane, Figure 10b shows the contours from the mid-plane, and Figure 10c displays the contours from the front plane in a comparative manner. Upon detailed examination of these contours, it is evident that low-pressure regions formed in the middle of the UAVs. Approximately \(-\)50 Pa pressure is observed on the opposing propeller surfaces of the UAVs positioned at the top. While it can be anticipated that the UAVs positioned above could affect those below, it has also been determined that they are affected by  
Figure 4:1 Velocity on vertical lines. the airflow generated as they approach each other horizontally. The total pressure lines resulting from the interaction of near-UAVs are presented both horizontally and vertically in Figures 11 and 12. The total pressure below 2.5 m from the UAVs is approximately 40 Pa. The distributions of total pressure are illustrated in Figure 4:2 Upon examination of the data lines Y600 and Y525, located 20 cm under the origins of the propeller rotating axis at X = 220 cm and 345 cm, approximately 200 Pa is observed at Y600, while it is around 130 Pa at Y525. As the propeller tips progress towards, this pressure increases up to 200 Pa. On the lines located 40 cm under the propeller origins, a maximum total pressure of 110 Pa at Y580 and 130 Pa at Y505 is observed. As the downward flow progresses, the distribution of pressure lines is observed to spread. On lines Y560 to Y485, under the lower row of UAVs, the pressure reaches up to 85 Pa at Y485, while under the upper row of UAVs, it remains under 65 Pa at Y560. The total pressure plot derived from vertical data lines is displayed in Figure 4:3 These vertical data lines are taken from a range of X220 to X345. Between Y 620 cm and 600 cm, the total pressure is increased at the UAVs positioned above. Y = 600 cm, the pressure reaches approximately 210 Pa on the X220 and X345 lines, while it is around 125 Pa on the X245 and X320 lines. It remains below 100 Pa at Y = 580 cm and is around 40 Pa at Y = 560 cm. Subsequent to the UAVs positioned below, the pressure is measured at 120 Pa at Y = 525 cm and reaches around 145 Pa near Y = 515 cm. The pressure between the axis lines ranges between 30 and 40 Pa at Y = 300 cm. Upon examination of the central axis lines (X270, X282.5, and X295), under the upper row of UAVs, it is approximately 10 Pa at Y = 600 cm, and a vacuum effect is observed as we approach towards the lower row of UAVs. The pressure converges at the same level as the other axis lines towards Y = 300 cm. Pressure distributions become more uniform with distance from the UAVs. Dynamic and static pressure values are also illustrated in Figure 4:4 The pressure and dynamic pressure plots taken from the front and rear axis planes are comparatively presented. The planes representing the front are denoted as \"F\", whereas those representing  
Figure 4:5 Total pressure contours: (**a**) rear plane; (**b**) mid-plane; (**c**) front plane.