Analysis Of Motion Response Of Single Point Mooring Shuttle Tanker In Wave

The shuttle tanker is widely used in FPSO, oil platforms and the shore-base crude oil transportation. The mooring way of shuttle tanker is different from the real project, and the single point mooring form is widely used in various oil development models in the sea.The shuttle tanker moored by single point mooring in offloading operation will have translational motion (surge, sway and yaw) of wide extent and long period due to the environmental effect such as wind,wave and current.Wide extent motion of the shuttle tanker will result in large tension of the cable and even cause collisions with other offshore structures.In order to study the motion characteristics of the shuttle tanker in the wave and the effect of different parameters on the motion of the shuttle tanker, a series of model tests in wave basin are conducted in Harbin Engineering University. The typical shuttle tanker of 105,000 tons and a scale ratio of 1:40 are used in the test, free decay test, RAO test and motion test of the shuttle tanker in irregular waves are respectively conducted. The tests in irregular waves record the motion of six degrees of freedom of the shuttle tanker moored by single point mooring in irregular waves, including surge, sway, yaw, roll, pitch and heave.The motion results of six degrees of freedom of the tanker with different draft, wave conditions, cable length and stiffness are get in the tests, the motion characteristics of the tanker in the wave are obtained with the test results of the shuttle tanker in the wave. The motion characteristics are explained and the effect of different parameters on the tanker motion is analyzed.Moreover, the numerical model of the shuttle tanker is established, and hydrodynamic parameters are obtained by frequency domain analysis, including RAO, QTF and so on, and the damping term of the tanker in the wave is analyzed. Due to the low frequency motion characteristics of the tanker, the time domain method is used and then the motion of the tanker in the wave and the tension of the cable are acquired.