Stiesdal. Physical model testing of the TetraSpar floater in two configurations

Transcription

1 Physical model testing of the TetraSpar floater in two configurations M Borg a, H Bredmose a, H Stiesdal b, B Jensen c, RF Mikkelsen a, M Mirzaei a, A Pegalajar-Jurado a, FJ Madsen a, TRL Nielsen a, AK Lomholt a a DTU Wind Energy, Kgs. Lyngby, Denmark b Stiesdal Offshore Technologies, Odense, Denmark c DHI, Hørsholm, Denmark EERA DeepWind th January 2018 Trondheim, Norway Stiesdal

2 Outline Introduction TetraSpar concept Experimental setup Example Results Conclusions 2

3 Introduction Scientific ambitions Improving SoA wind-wave testing Detailed hydrodynamic testing Fault & transient conditions Tech. development ambitions Proof-of-concept De-risk concept Stiesdal Collaborative research project 3

4 The TetraSpar concept Concept developed by Stiesdal Offshore Technologies Rationale: 4

5 Experimental setup: wave basin DHI deep-water wave basin with 4 x 4 m2 wind generator 5

6 Experimental setup: floater configurations Semi Spar 6

7 Experimental setup: wind turbine model DTU 10MW RWT 1:60 scale model from previous campaigns [1-3] Match steady thrust curve 75% increased chord Rotor I Collective blade pitch control New rotor design Match d(c T )/dθ 30% increased chord Steady thrust mismatch Improve aerodynamic damping Rotor II 7

8 Experimental setup - instrumentation 8

9 Experimental program Environmental conditions Test matrix 9

10 Experimental program selected results System damping Dynamic response of both configurations in ULS condition (EC11) Dynamic response of spar in focused wave group Environmental conditions Test matrix 10

11 Results system damping Identification of system damping free decay tests in 6 DOF, 10 repetitions Roll example: Roll [deg] 11

12 12

13 Results ULS waves only Motion response 13

14 Results ULS waves only Motion response

15 Results ULS waves only Acceleration response 15

16 Results ULS waves only Acceleration response 16

17 Results ULS waves only Acceleration response 0.24g 0.43g 17

18 Results ULS waves only Counterweight line tensions 18

19 Results ULS waves only Counterweight line tensions 19

20 Results Focused wave group EC11 H = 0.33m (19.5m) Spar response 20

21 Results Focused wave event EC11 H = 0.33m (19.5m) Spar response 21

22 Conclusions Testing of TetraSpar in semi and spar configurations Nonlinear system damping Significant subharmonic wave forcing C/W tensions dominated by inertia loads WT operation observed to reduce max acceleration References [1] A. M. Pegalajar Jurado, A. M. Hansen, R. Laugesen, R. F. Mikkelsen, M. Borg, T. Kim, N. F. Heilskov, H. Bredmose, Experimental and numerical study of a 10MW TLP wind turbine in waves and wind, Journal of Physics: Conference Series (online) 753 (2016) [2] H. Bredmose, F. Lemmer, M. Borg, A. Pegalajar-Jurado, R. Mikkelsen, T. Larsen, T. Fjelstrup, W. Yu, A. Lomholt, L. Boehm, J. Azcona, The Triple Spar campaign: Model tests of a 10 MW floating wind turbine with waves, wind and pitch control, Energy Procedia (2017), 137, pp [3] F. J. Madsen, T. R. L. Nielsen, Experimental and numerical study of the scaled DTU 10MW floating wind turbine on a TLP platform, MSc thesis, Department of Wind Energy, Technical University of Denmark, (2017). 22

23 Thank you for your attention Stiesdal 23