Nonlinear Destructive Interaction between Wind and Wave Loads Acting on the Substructure of the Offshore Wind Energy Converter: A Numerical Study
Abstract
:1. Introduction
2. External Forces Acting on the Offshore Wind Energy Converter
2.1. Wind Force
2.2. Aerodynamic Damping
2.3. Random Wave Force
2.4. Hydrodynamic Damping
3. Monte Carlo Simulation of the Wind Velocity
3.1. Kaimal Spectrum and Cross-Spectrum
3.2. Monte Carlo Simulation
4. Numerical Simulation of Random Waves Using the Random Phase Method
- Define a target wave energy spectrum.
- Choose the sample frequency and the resolution of the spectrum (half the number of Fourier components) . This yields a frequency domain resolution of . The discrete wave energy spectrum can be written as (see Figure 7):
- Calculate the N complex Fourier coefficients by picking a random phase between 0 and 2π for all frequencies smaller than the Nyquist frequency . A and B are given by:
- Mirror the N Fourier components into the Nyquist frequency in order to obtain a Hermitian Fourier transform
- Apply the inverse Fourier transform to and calculate the time series of the water surface displacement as follows
5. Equations of Motion for the Offshore Wind Energy Converter
6. Numerical Simulation
6.1. Numerical Results
6.2. Restriction on the Deflection of the Converter Caused by the Bumpy Water Surface and the Ensuing Large Eddy
7. Conclusions
Funding
Acknowledgments
Conflicts of Interest
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10.1314 | 2.059E + 11 | 7.980E + 3 | 1.024E + 3 | 1.05 | 1.0 | 0.5 |
Wind | Waves | |
---|---|---|
RUN 1 | Random Wind [U10 = 10.13 m/s] | Random Waves [Hs = 5 m, Tp = 10 s] |
RUN 2 | Random Wind [U10 = 10.13 m/s] | NO WAVES |
RUN 3 | Random Wind [U10 = 10.13 m/s] | Regular Waves [H = 5 m, T = 10 s] |
RUN 4 | Random Wind [U10 = 10.13 m/s] | Regular Waves [H = 10 m, T = 10 s] |
RUN 5 | Random Wind [U10 = 10.13 m/s] | Regular Waves [H = 5 m, T = 5 s] |
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Cho, Y.J. Nonlinear Destructive Interaction between Wind and Wave Loads Acting on the Substructure of the Offshore Wind Energy Converter: A Numerical Study. J. Mar. Sci. Eng. 2020, 8, 999. https://doi.org/10.3390/jmse8120999
Cho YJ. Nonlinear Destructive Interaction between Wind and Wave Loads Acting on the Substructure of the Offshore Wind Energy Converter: A Numerical Study. Journal of Marine Science and Engineering. 2020; 8(12):999. https://doi.org/10.3390/jmse8120999
Chicago/Turabian StyleCho, Yong Jun. 2020. "Nonlinear Destructive Interaction between Wind and Wave Loads Acting on the Substructure of the Offshore Wind Energy Converter: A Numerical Study" Journal of Marine Science and Engineering 8, no. 12: 999. https://doi.org/10.3390/jmse8120999
APA StyleCho, Y. J. (2020). Nonlinear Destructive Interaction between Wind and Wave Loads Acting on the Substructure of the Offshore Wind Energy Converter: A Numerical Study. Journal of Marine Science and Engineering, 8(12), 999. https://doi.org/10.3390/jmse8120999