Numerical Simulation Of Aerodynamic Characteristics And Flow Control Mechanism On Axial-flow Fan Blade

Axial flow fans play a great role in the industry and agriculture, its blades are the energy exchange components, the shape of blades affect the tip vortex intensity directly, the flow around the blades also contain much complicate flow mechanism.At the same time, its aerodynamic characteristic not only influence the efficiency of axial flow fans directly, but also the service life and noise. However, along with the modern life,more and more people are paying attention to the energy conservation, as long as the noise produced by the axial flow fan blades.The issue of how to improve the aerodynamic mechanism of fan blades so as to enhance the working efficiency is causing more and more concern.This paper, in order to improve the aerodynamic characteristics and reduce the noise, put forward a new3-D wavy airfoil blade which can delay the stall. The aerodynamic characteristic such as complicated flow structure, vorticity distribution at a series of Angles Of Attack(00≤α≤200) were simulated numerically by Computational Fluid Dynamics software (FLUENT), after compare with the two different airfoils, the mechanism of lift enhancement and delaying the stall on new3-D wavy airfoil was investigated deeply. It is observed that:because of the sine wavey shape of the new3-D wavy airfoil blade, it has a gradual lift coefficient curve in the stall aera comparing with the standard NACA0012airfoil.When Angle Of Attack is smaller than12degrees, the standard NACA0012airfoil has a higher lift, but when Angle Of Attack is bigger than12degrees, lift of new3-D wavy airfoil was increased by approximately20%. By thus, nine axial flow fans models with different vane numbers and installation angle were set up to discuss the engineering applicability of new3-D wavy airfoil by PRO/E, it is found that not all the parameters in this paper can improve the aerodynamic characteristic of the standard blade fans through the comparison of the flow pathlines and vorticity distribution on wind protecting ring. Only when the installation angle is bigger than15degrees, can wavy airfoil fans have improvement. At the same time,when the wavy airfoil fan has five blades and18degrees installation angle, the aerodynamic characteristic improve most obviously. As respect, the new3-D wavy airfoil improve the aerodynamic characteristics of axial flow fans.