Abstract: Against the existing problem that forest fire - fighting equipment cannot fully adapt to the harsh environment of forest fire, a kind of water - saving, environmental protection, efficient and safe electric control self - propelled air - water fire - fighting equipment is designed. The structure of the self - propelled air - water fire extinguisher is designed with Solidworks, and the axial flow fan is selected. Fluent software is used to analyze the internal flow field of axial - flow fan, establish the model, and obtain the flow chart and velocity cloud chart. Analysis shows that the whole equipment meets the fire - fighting requirements. Finally, the prototype is trial manufactured, and the functional test of the prototype is completed. The test results show that the fire - fighting time of the prototype is within the controllable range, which proves that the design of the machine meets the expected design requirements.

Key words: axial flow fan, fan duct, internal flow field, mathematical simulation