1. Static drift

• Fr = 0.138 (□), 0.280 (○), 0.410 (∆)
• Color code:
  • Black = roll fixed condition
  • Green = roll free condition

Heave	Pitch	Roll

• Heave z and pitch θ motions are quadratic with drift angle β.
• Roll f motion is cubic with β.
• The effect of roll on heave motion is small
• Pitch and roll motions are strongly coupled each other.

2. Dynamic Tests

1) Time histories

Fr = 0.280 results:

• Heave and pitch motions time histories are the 2nd-order harmonic dominant oscillations superposed on mean values.
• Roll motion time history is the 1st-order dominant harmonic oscillation.

2) Harmonic amplitudes (pure yaw test)

• Color code:
  • Black = roll fixed condition
  • Green = roll free condition

Harmonic	Heave	Pitch
0th
2nd

• Both of the 0^th- and 2^nd-order harmonics are quadratic with r_max.
• The effect of roll on heave motion is small
• The effect of roll on pitch motion is mainly to the 2nd-order harmonic, i.e., the pitch motion amplitude.