Numerical simulation for prediction of aerodynamic noise characteristics on a HAWT of NREL phase VI |
| |
Authors: | Jang-Oh Mo and Young-Ho Lee |
| |
Affiliation: | (1) University of California, Davis, CA, USA;(2) Department of Mechanical and Aerospace Engineering, University of California, Davis, CA 95616-5294, USA |
| |
Abstract: | The purpose of this study is to numerically predict the characteristics of aerodynamic noise generated from rotating wind
turbine blades according to wind speeds using commercial CFD code, FLUENT. The near-field flow around a HAWT of NREL Phase
VI is simulated directly by LES, whereas the far-field aerodynamic noise for frequencies below 500 Hz is modeled using FW-H
analogy. As there was no experimental noise data, we first compared aerodynamic noise analysis with experimental data. This
result showed a difference of power outputs by 0.8% compared with the experimental one with 6.02 kW. Then the characteristics
of aerodynamic noise were predicted at a specific location P1 according to IEC 61400-11 international standard. When the wind
turbine blades rotate with time, tip-vortices occur at the tip of two blades and are generated periodically in a circle. These
vortices in the vicinity of the blade tip cause intense aerodynamic noise due to the tip vortex-trailing edge interaction
by local cross flows along the trailing edge. In a wind speed of 7m/s the sound intensity ratio of quadrupole to dipole at
P1 location is about 21.1%, but as wind speed increases the sound intensity ratio increases up to 54.3% in the case of no-weighted
correction. This means that there is a considerably close relation between the quadrupole noise by small and large scales
and the increase of wind speeds. With the purpose of a rough prediction of sound power level, CFD results were compared with
a simple model of previous researchers and showed a good agreement with one by Hagg of three other models. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|