# Analysis of Flow Field Characteristics in the Three-Phase Jet Fire Monitor Head
## 3 Results and Discussion
### Analysis of the Influence of Supporting Blade Length on the Flow Field inside the TPfFM Head
As \(L_{f}\) increases, the \(\Delta p_{o}\) across the IFF shows a fluctuating upward trend, peaking at 864.19 kPa for \(L_{f}\) = 70 mm and dropping to a minimum of 861.32 kPa for \(L_{f}\) = 50 mm. Overall, increasing \(L_{f}\) tends to increase the PD across the monitor head, with local fluctuations. Figure 14: Line chart of changes in boundary parameters of IFF with different \(L_{f}\). Figure 13: Line chart of changes in flow field parameters of cross-section d with different \(L_{f}\). Increasing the \(L_{f}\) causes the area after the flow has passed through the powder tube to be completely divided into different areas by the support blade. Due to the disturbance of the powder pipe, the kinetic energy of the water flow at the powder pipe is not the same, and the subsequent kinetic energy exchange is not possible, resulting in the decline in uniformity at the outlet. In summary, increasing \(L_{f}\) does not significantly improve the velocity distribution uniformity at the nozzle outlet, and the PD across the monitor head varies slightly. However, the significant reduction in X and Y direction velocity components at cross-section d lowers the average TKE from 3.817 m\({}^{2}\)/s\({}^{2}\) to 2.964 m\({}^{2}\)/s\({}^{2}\), a 22.37% reduction, indicating a notable decrease in local TKE. Extending the supporting blades within the limited space can reduce local pressure losses to some extent. Analysis of the Influence of the Distance between the Supporting Blade and the Bending Section of the Powder Nozzle on the Flow Field inside the TPJFM Head  
A numerical simulation of the IFF of a TPJFM head was conducted by varying \(L_{pf}\) = 25-75 mm, while keeping other parameters at their initial values. The impact of \(L_{pf}\) on the IFF was analyzed. According to Figure 15, at the Z = 0 mm cross-section, as \(L_{pf}\) increases, the water flow near the edge of the upper supporting blades shifts from a direction perpendicular to the nozzle axis to one along the nozzle axis, reducing the radial and tangential velocity components. At the Z = 10 mm cross-section, a vortex forms between the bent section of the powder injection pipe and the upper supporting blades. As \(L_{pf}\) increases, the vortex area remains largely unchanged, but the vortex core moves towards the nozzle inlet, smoothing the flow around the upper supporting blades. At the Z = 20 mm cross-section, the influence of the powder injection pipe persists, and vortices are visible. With increasing \(L_{pf}\), the upper vortex zone shifts from a smaller flow area near the upper supporting blades to a larger flow area, increasing the proportion of flow along the nozzle axis and reducing radial and tangential velocity components. At the Z = 30 mm cross-section, the distance from the nozzle's bent section reduces the impact on flow, and the flow speed distribution and streamlines remain largely unchanged with varying \(L_{pf}\). Figure 15: Streamlines of cross-sections with different \(L_{pf}\). From the TKE cloud diagram at the Z = 0 mm cross-section in Figure 16, it is observed that with increasing \(L_{pf}\), the area of the high TKE region from the bending section of the powder pipe to the upper supporting blade increases gradually, but the peak TKE value in the region decreases significantly. At the Z = 10 mm cross-section, as \(L_{pf}\) increases, the high TKE region gradually moves from the upper supporting blade to the bending section of the powder pipe, and the TKE intensity decreases. At the Z = 20 mm cross-section, the high TKE region shifts similarly, and the peak TKE decreases. When \(L_{pf}\) = 25 mm, the local TKE near the nozzle outlet edge of the upper supporting blade reaches 13 m\({}^{2}\)/s\({}^{2}\), while at \(L_{pf}\) = 75 mm, the local TKE at the same position decreases to 7 m\({}^{2}\)/s\({}^{2}\), a reduction of 46%. At the Z = 30 mm cross-section, the structural influence of the powder-pipe bending section is minimal, and the overall TKE intensity is significantly lower than that in the Z = 0 mm, Z = 10 mm, and Z = 20 mm planes.