Experimental determination of water motions inside a moonpool

AuthorsBastien Abeil, MSc
Conference/JournalProceedings of the ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering OMAE2017, Trondheim, Norway
DateJul 14, 2017

The substantial water motions that can occur inside a moonpoolwhen a ship is operating in a formed sea represent a criticalissue for operators, as they imply an interruption of subsea activities (e.g. delay in ROV deployment) or even a threat to thesurvival of the equipment placed inside or around the moonpool(e.g. riser connected to a BOP). In a perspective of reducingdowntime caused by moonpool inactivity, substantial effort hasbeen made over the past year to better understand the circumstances of such water dynamics and devise mitigation measures. Works of among others Fukuda [1] or Molin [2] show that the moonpool motions can be described as either piston mode, in other words a vertical displacement of the watercolumn, or as horizontal sloshing modes, which natural frequencies can be approximated by closed-form expressions involving moonpool geometry and draught. The effect of damping devices, such as side wall flanges, has been widely investigated, notable publications include those of Fukuda [1] and Aalbers [3].State-of-the-art prediction of moonpool flows has undergonesome significant changes over the last years.

Tags
stability, seakeeping and ocean engineeringwaves, impacts and hydrostructuralmeasurements and controldata sciencerenewablesoil and gasinfrastructuremarine systemslife at seaseakeepingtransport and shippingmodel testingsloshingdampingoffshore engineering