ON THE SEAKEEPING RESPONSE VALUATION IN RANDOM SEA STATE CONDITIONS OF A LARGE LNG LIQUEFIED NATURAL GAS CARRIER

This seakeeping study refers to a large LNG liquified natural gas carrier with 289.3 m length, slender mono-hull, and fine shapes at both ends. From the loading cases of the large LNG carrier, two relevant are selected, full cargo and heavy ballast. The top speed of the large LNG carrier is 22 knots. To ensure the basis of the seakeeping response valuation in a random sea state, the navigation unrestricted conditions are modeled by the averaged ITTC wave power density spectrum. This study applies a linear strip theory hydrodynamic formulation for unrestricted water depth, delivering directly in the frequency domain the oscillations’ response amplitude operators. For the roll oscillations, this study includes the LNG carrier gravity center vertical position influence evaluation and the equivalent roll dampers effect. The short-term dynamic response for the random waves is evaluated by seakeeping criteria, delivering the safety navigation capabilities of the large LNG carrier.