Numerical and experimental investigation on effect of installation angle of rotor blade on axial flow fan

摘要

The effect of rotor blade installation angle on the flow field and performance of axial flow fan is presented in this paper. CFD simulation and experimental investigations are carried out with different value of installation angle. First, the inner flow fields of axial fan were simulated and analyzed by using the RNG k-? turbulent model and sliding mesh method of Fluent 6.3 software. Then, a five-hole probe was employed to measure the inner flow field of axial fan, and the variation tendency of velocity and pressure in testing section are found in good agreement with numerical results. The research shows that: with the increasing of installation angle, the lower pressure area induced by impact loss decreases in pressure side, but if installation angle is reduced, the impact loss happened in suction side will be more serious and the wake loss will also be deteriorated. The average total pressure has a trend of markedly increasing at the outlet of rotor; Reversed flow will happen in blade pressure side when installation angle is smaller in off-design condition and the smaller the installation angle, the larger the reverse flow area. Volume flow rate, pressure and torque of fan present an increasing tendency in various degrees with increasing of installation angle, and the fan total efficiency increases at first and then decrease. The total efficiency reduces 3.77% with total pressure drops 23.7% under the decreasing installation angle of 11°, and the peak value arrived at design angle of installation.