Rotating Axial-flow Fan Design Theory And Methods

Counter rotating axial fan is a kind of down-hole long distance ventilated equipments that just applied in recent years; the in-depth research of it can ensure the safe production of the coalmine. The research of the counter rotating axial fan still stay at the steady research and the low speed system, which makes the counter rotating axial fan occurs many problems in the course of running, so it's necessary to progress the more deep-seated analysis to the design theory and method of the counter rotating axial fan.Firstly through the tested check of the counter rotating axial fan which the author participated in by oneself, the macroscopically of the performance is completed; at the same time it is further proved that the counter rotating axial fan really has higher compression ratio, flow rate and wider stable work scopes by means of the measurement and analysis of steady flow-field between stages.Secondly, the thesis analyzes the influence of the two aerodynamic design methods (the constant circulation and the varied circulation) to the aerodynamic characteristics of the counter rotating axial fan, and the allocation rule of the compression work along the blade height, and swept-curved space mould of blades are also discussed.Thirdly, in the foundation of velocity triangle, the thesis analyzes the theories characteristic of the two stage impeller in detail and puts forward the method of preventing the overload of two-step motor. Furthermore a new design method of the counter rotating axial fan is also put forward on the basis of concerning literature.Finally the thesis preceded the finite element analysis to the strength of impeller.