## 3 Results and Discussion
### CFD Analysis
For S1 and S-1 configurations, the minimum values of shear stresses correspond to minimum seat to valve distance (H1), while for S0 configuration it corresponds to the maximum seat to valve distance (H4). The variations in shear stress highlight the complex flow patterns and boundary interactions within the valve. higher turbulent kinetic energy compared to others. This suggests that specific nozzle-seat combinations may promote more turbulence within the valve. In the case of water environment, the shear stress is notably affected by nozzle position and seat-to-valve distance. Highest shear stress is observed in the S0 and S1 nozzle positions at 3 mm seat-to-valve distance. Smaller seat-to-valve distances generally result in higher shear stress values. It can be also observed that TKE varies significantly with nozzle position and seat-to-valve distance. Maximum TKE values are found in the S0 and S-1 positions at 2 mm seat-to-valve distance. Pressure values vary considerably across different configurations. In general, the S0 and S1 configurations exhibit higher pressure values than the S-1 configuration. Additionally, within each configuration, pressure tends to decrease with an increase in seat-to-valve distance. These findings suggest that the choice of nozzle position and seat-to-valve distance significantly affects pressure distribution on the seat. Figure 14: Shear stress variation in case of plate (air environment). Figure 13: Water pressure variation in case of plate. The shear stress values decrease with seat-to-valve distance, the highest values correspond to S1 configuration, except at H4 distance, where S0 presents the higher shear stress. These variations in shear stress highlight the complex fluid dynamics and boundary interactions occurring on the seat. Turbulent kinetic energy varies significantly, reflecting the turbulence present in the airflow. In an air environment, generally, the turbulent kinetic energy decreases with seat-to-valve distance until H3. Some configurations, such as S0-H1 and S0-H2, show higher turbulent kinetic energy values compared to others. This suggests that specific nozzle-seat combinations can promote greater turbulence around the seat area. For example, Figure 24a,b shows the current lines in the case of S0-H1 flow for the air and water environment, respectively. In Figures 25 and 26, the distributions of pressure, shear stress and turbulence kinetic energy for plate and seat, respectively, are presented. Figure 16: Turbulent energy variation in case of plate (air environment). Figure 15: Shear stress variation in case of plate (water environment). Figure 19: Water pressure variation in case of seat. Figure 17: Turbulent energy variation in case of plate (water environment). Figure 9:0 Air pressure variation in case of seat. Figure 9:1 Shear stress variation in case of seat (water environment). Figure 9:2 Turbulent energy variation in case of seat (air environment). Figure 9:3 Turbulent energy variation in case of seat (water environment). Figure 9:4 Airflow streamlines, case S0-H1: air (**a**); water (**b**). Figure 9:5 _Cont._  
Figure 9:6 CFD results for plate, (case S0-H1): pressure (**a**), shear stress (**b**), turbulence kinetic energy (**c**). Figure 9:7 _Cont._  
Figure 9:8 CFD results for seat, (case S0-H1): pressure (**a**), shear stress (**b**), turbulence kinetic energy (**c**).