Acoustic Noise from Tandem Wind Rotors of Intelligent Wind Power Unit

• Published in: Journal of thermal science 2010-06, Vol.19 (2), p.120-125
• Main Authors: Kubo, Koichi, Mihara, Nobuhiko, Enishi, Akira, Kanemoto, Toshiaki
• Format: Article
• Language: English
• Subjects: Classical and Continuum Physics; Engineering Fluid Dynamics; Engineering Thermodynamics; Heat and Mass Transfer; Physics; Physics and Astronomy; 外转子; 智能型; 转动力矩; 转子平衡; 风噪声; 风电机组
• ISSN: 1003-2169; 1993-033X
• DOI: 10.1007/s11630-010-0120-7

The authors had invented the unique wind power unit composed of the large-sized front wind rotor, the small-sized rear wind rotor and the peculiar generator with the inner and the outer rotational armatures without the conventional stator. This unit is called ＂Intelligent Wind Power Unit＂ by the authors. The front and the rear wind rotors drive the inner and the outer armatures, respectively, while the rotational torque is counter-balanced between both armatures/wind rotors. This paper discusses experimentally the acoustic noise from the front and the rear wind rotors. The acoustic noise, in the counter-rotating operation, is induced mainly from the flow interaction between both rotors, and has the dominant power spectrum density at the frequency of the blade passing interaction. The noise is caused mainly from the turbulent fluctuation due to the flow separation on the blade, when the rear wind rotor stops or rotates in the same direction as the front wind rotor.