Abstract:
Evaluation of wind loads on offshore structures is crucial in the design and can be decisive in the design of novel structures or innovative designs, such as the large FLNG vessels analyzed in this work, with 450 m length, 81 m draught and a height of 38 m. The tests were carried out in a wind tunnel with a 1:200 scale model attached to a six freedom force and torque sensor subjected to an ocean far from shore atmospheric boundary layer with potential coefficient of 0.10. Two situations were tested: the vessel alone under two different drafts: 17.08 m (fully loaded) and 10.64 m (ballast) in the prototype scale. The same model was tested with the presence of a shuttle vessel, in both tandem and side-by-side configurations. The shuttle is a MossPherical type LNG carrier with 300 m length, 52 m draught and a height of 28 m. The results show that the shuttle vessel has little influence on the FLNG mean wind load in both side-by-side and tandem configuration. The maximum load coefficient observed for the FLNG were: surge coefficient 0.4 , sway coefficient 1.5, roll coefficient 0.3 and yaw coefficient 0.3. On the other hand the FLNG has a large influence on the shuttle vessel, reducing the wind load, according to the relative position. When in tandem configuration, the reduction is of the order of 50% on the drag coefficient and 75% on the yaw moment coefficient since the shuttle vessel was in the wake of the FNLG.
Reference:
JABARDO, Paulo José Saiz; MARTINS, Gabriel Borelli; NADER, Gilder; ROSETTI, Guilherme Feitosa; NIHIMOTO, Kazuo. Wind loads on the topside of a FLNG vessel: wind tunnel model tests. In: INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING – COBEM, 24th., 2017, Curitiba. Anais… 10 p.
Evaluation of wind loads on offshore structures is crucial in the design and can be decisive in the design of novel structures or innovative designs, such as the large FLNG vessels analyzed in this work, with 450 m length, 81 m draught and a height of 38 m. The tests were carried out in a wind tunnel with a 1:200 scale model attached to a six freedom force and torque sensor subjected to an ocean far from shore atmospheric boundary layer with potential coefficient of 0.10. Two situations were tested: the vessel alone under two different drafts: 17.08 m (fully loaded) and 10.64 m (ballast) in the prototype scale. The same model was tested with the presence of a shuttle vessel, in both tandem and side-by-side configurations. The shuttle is a MossPherical type LNG carrier with 300 m length, 52 m draught and a height of 28 m. The results show that the shuttle vessel has little influence on the FLNG mean wind load in both side-by-side and tandem configuration. The maximum load coefficient observed for the FLNG were: surge coefficient 0.4 , sway coefficient 1.5, roll coefficient 0.3 and yaw coefficient 0.3. On the other hand the FLNG has a large influence on the shuttle vessel, reducing the wind load, according to the relative position. When in tandem configuration, the reduction is of the order of 50% on the drag coefficient and 75% on the yaw moment coefficient since the shuttle vessel was in the wake of the FNLG.
Reference:
JABARDO, Paulo José Saiz; MARTINS, Gabriel Borelli; NADER, Gilder; ROSETTI, Guilherme Feitosa; NIHIMOTO, Kazuo. Wind loads on the topside of a FLNG vessel: wind tunnel model tests. In: INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING – COBEM, 24th., 2017, Curitiba. Anais… 10 p.
