Avoiding wind turbine tonalities A structured, system based approach. Frederik Vanhollebeke ZF Wind Power Technology

Transcription

1 Avoiding wind turbine tonalities A structured, system based approach Frederik Vanhollebeke Wind Power Technology EWEA Wind Turbine Sound 2014

2 Avoiding wind turbine tonalities Agenda 1. Wind turbine sound sources 2. Wind turbine mechanical sound 1. Historical way of thinking 2. Versus experimental measurements 3. Avoiding wind turbine tonalities: ALARM research project EWEA Wind Turbine Sound 2014

3 Wind turbine sound Aeroacoustic sound Generated by aero-elastic interaction between the air, the rotating blades and the tower and nacelle. Determines overall level Radiates directly to the surroundings Broadband of nature Several noise mechanisms such as: Flow separation noise Turbulent layer trailing edge noise Leading edge noise Tip noise Petitjean et al. (2011) EWEA Wind Turbine Sound 2014

4 Wind turbine sound Mechanical sound Originates from mechanical components such as gearbox, generator, fans, => Mechanical tonalities occur at both wind turbines with gearbox or direct driven wind turbines Tonal of nature and only audible when above aerodynamic sound 110,0 Total SPL of 3MW gearbox at rated power = 92 db(a) Sound power level [db(a)] 100,0 90,0 80,0 70,0 60,0 50,0 40,0 30, Frequency [Hz] Petitjean et al. (2011) EWEA Wind Turbine Sound 2014

5 A-weighted sound pressure Wind turbine sound Mechanical sound - Challenges Challenges Wind turbines are installed closer to urbanised areas => increase in sound pressure Petitjean et al. (2011) EWEA Wind Turbine Sound 2014

6 A-weighted sound pressure Wind turbine sound Mechanical sound - Challenges Challenges Wind turbines are installed closer to urbanised areas => increase in sound pressure More stringent limits on total sound and tonal levels Petitjean et al. (2011) EWEA Wind Turbine Sound 2014

7 A-weighted sound pressure Wind turbine sound Mechanical sound - Challenges Challenges Wind turbines are installed closer to urbanised areas => increase in sound pressure More stringent limits on total sound and tonal levels Optimised blade design Petitjean et al. (2011) EWEA Wind Turbine Sound 2014

8 A-weighted sound pressure Wind turbine sound Mechanical sound - Challenges Challenges Wind turbines are installed closer to urbanised areas => increase in sound pressure More stringent limits on total sound and tonal levels Optimised blade design Low sound operating modes Petitjean et al. (2011) EWEA Wind Turbine Sound 2014

9 A-weighted sound pressure Wind turbine sound Mechanical sound - Challenges Challenges Wind turbines are installed closer to urbanised areas => increase in sound pressure More stringent limits on total sound and tonal levels Optimised blade design Low sound operating modes Tonal sound evaluation at very low wind speeds Petitjean et al. (2011) EWEA Wind Turbine Sound 2014

10 Wind turbine mechanical sound NOISE SOURCE Gearbox: gear excitation Gearbox: resonances TRANSFER PATH Wind turbine: drive train and other structural parts Wind turbine: radiating parts RECEIVER Tonality outside EWEA Wind Turbine Sound 2014

11 Wind turbine mechanical sound Historical way of thinking versus Experimental validation NOISE SOURCE Gearbox: gear excitation Gearbox: resonances TRANSFER PATH Wind turbine: drive train and other structural parts Wind turbine: radiating parts RECEIVER Tonality outside EWEA Wind Turbine Sound 2014

12 Wind turbine mechanical sound Historical way of thinking versus Experimental validation NOISE SOURCE Gearbox: gear excitation Gearbox: resonances TRANSFER PATH Wind turbine: drive train and other structural parts Wind turbine: radiating parts RECEIVER Tonality outside EWEA Wind Turbine Sound 2014

13 Wind turbine mechanical sound Historical way of thinking versus Experimental validation NOISE SOURCE Gearbox: gear excitation Gearbox: resonances TRANSFER PATH Wind turbine: drive train and other structural parts Wind turbine: radiating parts RECEIVER Tonality outside EWEA Wind Turbine Sound 2014

14 Wind turbine mechanical sound Historical way of thinking versus Experimental validation NOISE SOURCE Gearbox: gear excitation Gearbox: resonances TRANSFER PATH Wind turbine: drive train and other structural parts Wind turbine: radiating parts RECEIVER Tonality outside EWEA Wind Turbine Sound 2014

15 Wind turbine mechanical sound Historical way of thinking versus Experimental validation NOISE SOURCE Gearbox: gear excitation Gearbox: resonances TRANSFER PATH Wind turbine: drive train and other structural parts Wind turbine: radiating parts RECEIVER Tonality outside EWEA Wind Turbine Sound 2014

16 Wind turbine mechanical sound Historical way of thinking versus Experimental validation NOISE SOURCE Gearbox: gear excitation Gearbox: resonances TRANSFER PATH Wind turbine: drive train and other structural parts Wind turbine: radiating parts RECEIVER Tonality outside EWEA Wind Turbine Sound 2014

17 Wind turbine mechanical sound Historical way of thinking NOISE SOURCE TRANSFER PATH Gearbox: gear excitation Gearbox: resonances Wind turbine: drive train and other structural parts Wind turbine: radiating parts versus Experimental validation Experimental measurements show: Significant coupling between dynamic behaviour of both gearbox and wind turbine structure RECEIVER Tonality outside EWEA Wind Turbine Sound 2014

18 Wind turbine mechanical sound Historical way of thinking versus Experimental validation NOISE SOURCE Gearbox: gear excitation Resonances: gearbox + drive train + structural parts Experimental measurements show: Significant coupling between dynamic behaviour of both gearbox and wind turbine structure TRANSFER PATH RECEIVER Wind turbine: radiating parts Tonality outside Resonances are influenced by Gearbox design Wind turbine design & Resonances should be tackled by following a system based approach - a component approach alone will not be successful EWEA Wind Turbine Sound 2014

19 Avoiding wind turbine tonalities Concept Design Validation Troubleshooting Simple guidelines (based on information from other projects) System level dynamic simulation Acoustic radiation simulation SMART test rig measurements IEC measurements Field measurement campaign IEC measurements + Extensive field measurement campaign System level simulation EWEA Wind Turbine Sound 2014

20 Avoiding wind turbine tonalities Concept Design Validation Troubleshooting Simple guidelines (based on information from other projects) System level dynamic simulation Acoustic radiation simulation SMART test rig measurements IEC measurements Field measurement campaign IEC measurements + Extensive field measurement campaign System level simulation EWEA Wind Turbine Sound 2014

21 Avoiding wind turbine tonalities ALARM research project Concept Design Validation Troubleshooting Simple guidelines (based on information from other projects) System level dynamic simulation Acoustic radiation simulation SMART test rig measurements IEC measurements Field measurement campaign IEC measurements + Extensive field measurement campaign System level simulation EWEA Wind Turbine Sound 2014

22 Avoiding wind turbine tonalities ALARM Gear excitation System dynamics Virtual prototyping Advanced gear excitation calculations Development of gear excitation models Experimental Experimental validation of gear excitation Sound radiation Wind turbine mechanical sound EWEA Wind Turbine Sound 2014

23 Avoiding wind turbine tonalities ALARM Gear excitation System dynamics Virtual prototyping Advanced multibody and finite element modelling of the complete wind turbine Experimental In depth experimental validation of the gearbox (eigenmodes) Experimental validation of the wind turbine (eigenmodes, transfer paths, vibration levels) Sound radiation Wind turbine mechanical sound EWEA Wind Turbine Sound 2014

24 Avoiding wind turbine tonalities ALARM Gear excitation System dynamics Virtual prototyping Advanced coupled acoustic model of the complete wind turbine Experimental Experimental validation of the wind turbine Noise inside nacelle Noise outside (IEC locations) Noise radiation (HUGE acoustic camera) Sound radiation Wind turbine mechanical sound EWEA Wind Turbine Sound 2014

25 Avoiding wind turbine tonalities ALARM Concept Design Validation Troubleshooting IEC measurements remain conclusive Lessons learnt from ALARM: Optimal sensor set to investigate turbine dynamic behaviour (during wind turbine validation) Innovative analysis techniques to investigate wind turbine sound EWEA Wind Turbine Sound 2014

26 Avoiding wind turbine tonalities ALARM Concept Design Validation Troubleshooting Transition from blind design towards model based design Lessons learnt from ALARM: Wind turbine dynamic model is capable of predicting relevant dynamic phenomena Accuracy of the wind turbine dynamic model Insight in relevant dynamic behaviour EWEA Wind Turbine Sound 2014

27 Avoiding wind turbine tonalities ALARM Concept Design Validation Troubleshooting Transition from blind concept towards a concept in which generic insights from previous measurements / models are used. Lessons learnt from ALARM: There exist noise sensitive frequency ranges in any wind turbine that should be avoided in the concept! EWEA Wind Turbine Sound 2014

28 Wind turbine mechanical sound ALARM Conclusions Dynamics are determined by a coupled system behaviour A system based approach is key to understand the dynamic phenomena causing wind turbine tonalities Alarm has shown that wind turbine tonal behaviour can already be assessed during both concept & design! Open cooperation between wind turbine, gearbox and bushing OEM necessary to systematically avoid tonal wind turbine sound EWEA Wind Turbine Sound 2014

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