An investigation on the effects of irregular airfoils on the aerodynamic performance of small axial flow fans

• Published in: Journal of mechanical science and technology Vol. 27; no. 6; pp. 1677 - 1685
• Main Authors: Zhang, Li, Jin, Ying-Zi, Jin, Yu-Zhen
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2013; Springer Nature B.V; 대한기계학회
• Subjects: Aerodynamic noise; Aerodynamics; Airfoils; Axial flow; Blades; Computer simulation; Control; Dynamical Systems; Engineering; Industrial and Production Engineering; Mathematical models; Mechanical Engineering; Turbulent flow; Vibration; 기계공학; Aerodynamic noise; Irregular design; Large eddy simulation; Vortex; Performance; Noise reduction
• ISSN: 1738-494X; 1976-3824
• DOI: 10.1007/s12206-013-0416-0

In this paper, the effects of airfoils on the aerodynamic performance of small axial flow fans were investigated to reduce airflow turbulence on the blade surface and to improve the aerodynamic performance of small axial flow fans. Irregular airfoils where several convex grooves are bound in the blade pressure surface of the fans have two kinds. The wave-shaped edge is bound to the blade trailing edge of the fans and is designed from the smooth airfoil of the fans. The filtered N-S equations with the finite volume method and the standard k-ɛ turbulence model were adopted to carry out the steady simulation calculation. The large eddy simulation and the FH-W noise models were adopted to carry out the unsteady numerical calculation and aerodynamic noise prediction. The results of simulation calculation are in good agreement with the tests, which proves that the numerical calculation method is feasible. The spectrum characteristics of aerodynamic noise of the smooth airfoil and the two kinds of irregular airfoils were analyzed. Although the fans of the three airfoils are regarded as noise sources, the vortex distribution features in the unsteady flow field are also described. Noise reduction mechanisms of the irregular designs of the airfoils were also discussed. The results of this research may provide proof of the parameter optimization and the structural design of small axial flow fans with low noise.