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MINIMIZING THE TRAILING EDGE NOISE FROM ROTOR-ONLY AXIAL FANS USING DESIGN OPTIMIZATION

✍ Scribed by D.N. SØRENSEN


Book ID
102611753
Publisher
Elsevier Science
Year
2001
Tongue
English
Weight
391 KB
Volume
247
Category
Article
ISSN
0022-460X

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✦ Synopsis


Numerical design optimization was used to minimize the trailing edge noise of rotor-only axial fans. The design variables were: hub radius, number of blades, rotational speed of the rotor and spanwise distributions of chord length, stagger angle and camber angle. Imposed constraints assured a minimum pressure rise and non-stalled #ow conditions across the blades. A blade element model was used to calculate the aerodynamic performance of the fan and, furthermore, provided velocities used in the calculation of the trailing edge noise. Optimizations were made to (1) minimize trailing edge noise, ( 2) maximize e$ciency, and (3) minimize the rotational speed of the rotor. The resulting designs were compared and the potential bene"t of minimizing the trailing edge noise was found to be large. Also, the trailing edge noise was minimized while a constraint was imposed on the e$ciency. It was found that a considerable noise reduction could be gained with only a limited reduction in fan e$ciency. Finally, the dependency of the minimum trailing edge noise on the size of the hub radius was examined. From this, a hub radius existed, for which a minimum trailing edge noise was obtained, and small variations in hub radius could be made with only a limited increase in trailing edge noise.