The numerical simulation of internal three-dimensional flow in the axial-flow fire-fighting fan

Axial-flow axial fan is used as fire fighting parts in the axial-flow pneumatic extinguisher. The shape of axial impeller is the key factor affecting the internal flow field structure of fire-fighting fan, outlet total pressure and flow velocity. In order to understand the flow pattern of axial-flow fire-fighting fan thoroughly, according to N-S equations and k-¿ turbulence model, the internal three-dimensional viscous flow field of axial-flow fire-fighting fan was numerically simulated and many internal flow details, rules and performance parameters of axial-flow fan under the design working conditions was obtained. Numerical analysis shows that under the design working conditions, gas takes parallel flow from inlet and helically outflows from outlet as a whole, vortex generates at the blade tip area, some gas have reversed flow and lead to loss. The simulation results provide a theoretical basis for performance improvements of axial-flow fire-fighting fan.