## 4 Conclusions  
In this paper, an advanced flow-structure-acoustics framework has been developed and validated against load field measurements for the case of the 2.3 MW NM80 wind turbine under a moderate wind shear and a small and a large yaw angle. The code has been further used for studying and controlling noise generation from a wind turbine under a moderate wind shear and a small yaw, which is often the case when a wind turbine operates. Through analysis of the results, several conclusions are summarized here:  
1. Simulations based on the coupled Ellipsys3D/AL/Flex5 framework agreed well with field load measurements on the 2.3 MW NM80 turbine. Figure 15: Sound pressure level and A-weighted Sound pressure level from the wind turbine at 10 m/s wind speed: (**a**) SPL for Case 1; (**b**) A-weighted SPL for Case 1; (**c**) SPL for Case 2; (**d**) A-weighted SPL for Case 2; (**e**) SPL for Case 4; (**f**) A-weighted SPL for Case 4. It was observed that the wind shear had a significant impact on the flow field, which led to a fainter wake. The longitudinal wind speed was reduced by introducing yaw, which accordingly decreased the sound pressure level. 3. The reduction of sound pressure level under a moderate wind shear situation with a shear exponent of 0.3 was undertaken by a pitch adjustment, while the power and thrust coefficients generally became more undulant. The pitch adjustment techniques were only useful for the case with a wind shear. 4. Given the miscellaneous reasons causing the wind turbine noise and the complex relations in SPL prediction formulations, it was obviously found that SPL and AoA were not linearly related. This non-linear relationship was also confirmed by comparing the variation of AoA and SPL. 5. Through the comparison of SPL and A-weighted SPL, the pitch control implemented in this paper mainly affected the wind turbine noise at low frequencies, while unapparent effects occurred with high-frequency noise. 6. The mean SPL was reduced with 0.4 dB and the modulation depth was reduced slightly. Conceptualization, W.Z.S. ; Formal analysis, M.Z. ; Investigation, M.Z. ; Methodology, W.Z.S. ; Project administration, W.Z.S. ; Resources, W.Z.S. ; Software, M.S. and W.Z.S. ; Supervision, M.S., H.Y. and W.Z.S. ; Visualization, M.Z. ; Writing--original draft, M.Z. ; Writing--review & editing, M.S., H.Y. and W.Z.S. All authors have read and agreed to the published version of the manuscript. This paper was partially funded by the Danish Energy Agency in the project (EUDP2018, Journal nr. 64018-0084) and the Innovation Fund Denmark in the project entitled \"DecoWind--Development of low-noise and cost-effective wind farm control technology\" under project number (8055-00041B). The DanAero projects were funded partly by the Danish Energy Agency, (EFP2007. Journal nr. 33033-0074 and EUDP 2009-II. Journal nr: 64009-0258) and partly by self-funding from the project partners Vestas, Siemens Games Renewable Energy, LM Wind Power, Dong Energy and DTU Wind Energy. The authors declare  
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