Improvement of the performance of an axial fan with counter-rotation

Authors

Adel Ghenaiet - Laboratory of Energetics and Conversion Systems, Faculty of Mechanical Engineering, University of Sciences and Technology Houari Boumediene
Ibrahim Beldjilali - Laboratory of Turbomachinery, Fluid Mechanics and Energetic, Ecole Militaire Polytechnique

Abstract

The counter-rotation solution is preferred to increase the power and flow rates of fans. The aims of the present work are to experimentally and numerically characterize the aerodynamic performance of a counter-rotating fan (CRF) and investigate the effects of some design parameters such as the variable stagger angle and inter-distance. The baseline axial fan was modified by adding a rear rotor, a spherical nose and a tail fairing, thus a higher pressure rise is obtained from the conversion of a large part of swirl flow into a static pressure. The results reveal the effects of stagger angle and axial inter-distance on the improved aerodynamic performance and show the best setting parameters. Besides, the counter-rotation seems reducing the aerodynamic loading of both rotors and allowing working at a stable static pressure rise over a wide range of air flow rate.