Journal of Thermal Science

, Volume 22, Issue 5, pp 424–432 | Cite as

Numerical and experimental investigation on aerodynamic performance of small axial flow fan with hollow blade root

  • Zhang Li
  • Yingzi Jin
  • Dou Huashu
  • Jin Yuzhen


To reduce the influence of adverse flow conditions at the fan hub and improve fan aerodynamic performance, a modification of conventional axial fan blades with numerical and experimental investigation is presented. Hollow blade root is manufactured near the hub. The numerical and experimental results show that hollow blade root has some effect on the static performance. Static pressure of the modified fan is generally the same with that of the datum fan, while, the efficiency curve of the modified fan has a different trend with that of the datum fan. The highest efficiency of the modified fan is 10% greater than that of the datum fan. The orthogonal experimental results of fan noise show that hollow blade root is a feasible method of reducing fan noise, and the maximum value of noise reduction is about 2 dB. The factors affecting the noise reduction of hollow blade root are in the order of importance as follows: hollow blade margin, hollow blade height and hollow blade width. The much smoother pressure distribution of the modified fan than that of the datum fan is the main mechanism of noise reduction of hollow blade root. The research results will provide the proof of the parameter optimization and the structure design for high performance and low noise small axial fans.


small axial flow fan hollow blade root performance noise reduction mechanism 



air flow rate (kg/s)


hub ratio


impeller diameter(mm)


hub thickness (mm)


blade stagger angle


rotational speed (r/min)


static pressure (Pa)


tip clearance


volume flow rate (m3/s)


number of impeller blades


hollow blade height(mm)


hollow blade width(mm)


hollow blade margin(mm)




sound pressure level(dB)


range analysis


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Copyright information

© Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Zhang Li
    • 1
    • 2
  • Yingzi Jin
    • 1
  • Dou Huashu
    • 1
  • Jin Yuzhen
    • 1
  1. 1.Faculty of Mechanical Engineering & AutomationZhejiang Sci-Tech UniversityHangzhou, ZhejiangChina
  2. 2.Department of Application & EngineeringZhejiang Economic & Trade PolytechnicalHangzhou, ZhejiangChina

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