Objective
To develop a preliminary mooring system design (for the FPSO you designed) based on the consideration of steady wind/current/wave loads/motions, wave-frequency loads/motions, and slowly-varying loads/motions of the FPSO. Full loaded ship condition (100% loading) in 100-year survival sea environment is considered in the design and analysis.
- Under the head sea condition,
- determine steady wind, current, and wave drift loads on the FPSO;
- determine slowly-varying wave load on the FPSO; and
- determine wave-frequency motions of the FPSO
- Develop a preliminary design of the mooring system
- Compute load-excursion relations
- Compute:
- steady tension in the cable and steady horizontal displacement of the FPSO;
- wave-frequency tension in the cable;
- estimate (surge) natural frequency of the FPSO; and
- slowly-varying tension in the cable and slowly-varying displacement of the FPSO
- Determine:
- maximum tension in the cable and safety factor, and
- maximum displacement of the FPSO
- Assuming one cable is broken, repeat (c), (d), and (e)
- Discuss the performance of the designed mooring system and possible improvements for the design
Software
RISER-SIM (developed by MIT Professor Michael Triantafyllou)