Table 1 Comparison of change in computed sound power level, LwA for three and two blade rotors of a 2 MW wind turbine rotor blades at U10 = 10 m/s using BPM, Grosveld and Lowson methods
From: Influence of rotor solidity on trailing edge noise from wind turbine blades
Frequency (Hz) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
63 | 100 | 200 | 400 | 800 | 1000 | 2000 | 4000 | 5000 | 8000 | |
BPM | ||||||||||
SPL [dBA]3,blade | 61.3 | 73.0 | 88.6 | 97.0 | 94.9 | 94.3 | 89.7 | 82.4 | 79.4 | 72.0 |
SPL [dBA]2,blade | 56.3 | 68.0 | 83.6 | 92.0 | 89.9 | 89.3 | 84.6 | 77.3 | 74.3 | 67.0 |
Δ dBA | 5.0 | 5.0 | 4.9 | 5.0 | 5.0 | 5.0 | 5.1 | 5.1 | 5.1 | 5.1 |
Grosveld | ||||||||||
SPL [dBA]3,blade | 77.2 | 84.4 | 90.2 | 91.6 | 89.2 | 87.8 | 81.7 | 74.0 | 71.0 | 64.3 |
SPL [dBA]2,blade | 72.9 | 79.4 | 85.0 | 86.4 | 84.1 | 82.6 | 76.6 | 68.9 | 65.9 | 59.2 |
Δ dBA | 4.2 | 4.9 | 5.3 | 5.2 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 |
Lowson | ||||||||||
SPL [dBA]3,blade | 83.2 | 90.3 | 95.1 | 94.5 | 89.8 | 87.6 | 79.3 | 69.6 | 66.0 | 57.9 |
SPL [dBA]2,blade | 81.8 | 88.7 | 93.0 | 91.9 | 87.0 | 84.8 | 76.6 | 66.8 | 63.2 | 55.2 |
Δ dBA | 1.4 | 1.6 | 2.1 | 2.6 | 2.7 | 2.8 | 2.8 | 2.8 | 2.8 | 2.8 |