Ocean Systems Engineering Volume 6, Number 3, September 2016 , pages 233-244 DOI: https://doi.org/10.12989/ose.2016.6.3.233 |
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Frequency domain analysis of Froude-Krylov and diffraction forces on TLP |
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Ebrahim Malayjerdi and Mohammad Reza Tabeshpour
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Abstract | ||
Tension Leg Platform (TLP) is a floating structure that consists of four columns with large diameter. The diffraction theory is used to calculate the wave force of floating structures with large dimensions (TLP). In this study, the diffraction and Froude-Krylov wave forces of TLP for surge, sway and heave motions and wave force moment for roll, pitch degrees of freedom in different wave periods and three wave approach angles have been investigated. From the numerical results, it can be concluded that the wave force for different wave approach angle is different. There are some humps and hollows in the curve of wave forces and moment in different wave periods (different wavelengths). When wave incidents with angle 0 degree, the moment of diffraction force for pitch in high wave periods (low frequencies) is dominant. The diffraction force for heave in low wave periods (high wave frequencies) is dominant. The phase difference between Froude-Krylov and diffraction forces is important to obtain total wave force. | ||
Key Words | ||
TLP; hydrodynamic; wave forces; diffraction; Froude-Krylov; phase difference | ||
Address | ||
Ebrahim Malayjerdi : Mechanical Engineering Department, Sharif University of Technology, Tehran, Iran Mohammad Reza Tabeshpou: Mechanical Engineering Department, Center of Excellence in Hydrodynamics and Dynamics of Marine Vehicles, Sharif University of Technology, Tehran, Iran | ||