Dynamic response of a novel heave-compensated floating platform: design considerations and the effects of mooring

Investigations regarding the dynamic response of a novel heave-compensated floating platform have been carried out. The concept consists of a semi-submersible floating platform with an air chamber below its hull, aiming to keep the static platform buoyancy constant, thus effectively reducing heave motion and enabling its use under harsh environmental conditions as in the North and Norwegian seas. This work develops a dynamic response model for the concept platform in which hydrodynamic coefficients calculated using potential flow theory and mooring lines effects are considered. Calculations in both the frequency and time domain are performed, and results show that the air chamber and effects of the mooring lines are the most beneficial scenario to reduce the dynamic response, especially in terms of heave motion reduction at lower wave frequencies. Another observed benefit is the change of the heave resonance peak away from the typical observed frequency range of sea waves.