This paper presents 3D （three-dimensional） CFD （computational fluid dynamic） simulation to analyse the FIR （flow-induced response） especially the yaw motion of a buoyancy can. The numerical cases are conducted w...This paper presents 3D （three-dimensional） CFD （computational fluid dynamic） simulation to analyse the FIR （flow-induced response） especially the yaw motion of a buoyancy can. The numerical cases are conducted with a buoyancy can under different reduced velocities utilizing our in-house code naoe-FOAM-SJTU, a solver based on the open source toolkit OpenFOAM. SST-DDES （shear-stress transport-delayed detached-eddy simulation） model is applied to handle the flowseparation and overset grid method is utilized to solve a large amplitude 6-DOF （6 degrees of freedom） motions. Free decay test and VIM （vortex-induced motion） test are built numerically. In VIM cases, the responses of trajectory, amplitude, frequency are calculated in a series of reduced velocities. With the increase of reduced velocity, yaw frequency is increased, which is similar to surge and sway frequency. And yaw frequency is equal to the sway frequency, which is consistent with experimental results. Furthermore, comparing two cases, one fixed in rotation and the other one free in rotation, it can be concluded that release in the degree of rotation can decrease the sway amplitude but make no difference in the surge amplitude.展开更多
In recent years, attention has been focused on the spar platform for gas and oil exploitation in deep water. With the development of offshore technology, many new spar concepts have been put forward and fully studied....In recent years, attention has been focused on the spar platform for gas and oil exploitation in deep water. With the development of offshore technology, many new spar concepts have been put forward and fully studied. This paper presents the results of an experimental investigation on the hydrodynamic behavior of a new spar concept from Novellent Offshore LLC, USA, which is called Ceometrie Spar （G-spar）. A new type of buoyancy can concept from the same company, viz. Integratod Buoyancy Can （IBC）, is researched in the meantime. The G-spar and IBC models with a 1：70 scale are tested in the State Key Laboratory of Ocean Engineering at Shanghai Jiao Tong University for the global performance of the spar hull, in which the second-order wave drift force is involved, as well as the effect of heave plates on the motion characteristics and mooring force of the G-spar platform.展开更多
基金Acknowledgements This work is supported by the National Natural Science Foundation of China （51490675, 51379125, 11432009, 51579145）, Chang Jiang Scholars Program （T2014099）, Shanghai Excellent Academic Leaders Program （17XD1402300）, Shanghai Key Laboratory of Marine Engineering （K2015-11）, Program for Professor of Special Appointment （Eastern Scholar） at Shanghai Institutions of Higher Learning （2013022）, Innovative Special Project of Numerical Tank of Ministry of Industry and Information Technology of China （2016-23/09） and Lloyd＇s Register Foundation for doctoral student, to which the authors are most grateful.
文摘This paper presents 3D （three-dimensional） CFD （computational fluid dynamic） simulation to analyse the FIR （flow-induced response） especially the yaw motion of a buoyancy can. The numerical cases are conducted with a buoyancy can under different reduced velocities utilizing our in-house code naoe-FOAM-SJTU, a solver based on the open source toolkit OpenFOAM. SST-DDES （shear-stress transport-delayed detached-eddy simulation） model is applied to handle the flowseparation and overset grid method is utilized to solve a large amplitude 6-DOF （6 degrees of freedom） motions. Free decay test and VIM （vortex-induced motion） test are built numerically. In VIM cases, the responses of trajectory, amplitude, frequency are calculated in a series of reduced velocities. With the increase of reduced velocity, yaw frequency is increased, which is similar to surge and sway frequency. And yaw frequency is equal to the sway frequency, which is consistent with experimental results. Furthermore, comparing two cases, one fixed in rotation and the other one free in rotation, it can be concluded that release in the degree of rotation can decrease the sway amplitude but make no difference in the surge amplitude.
文摘In recent years, attention has been focused on the spar platform for gas and oil exploitation in deep water. With the development of offshore technology, many new spar concepts have been put forward and fully studied. This paper presents the results of an experimental investigation on the hydrodynamic behavior of a new spar concept from Novellent Offshore LLC, USA, which is called Ceometrie Spar （G-spar）. A new type of buoyancy can concept from the same company, viz. Integratod Buoyancy Can （IBC）, is researched in the meantime. The G-spar and IBC models with a 1：70 scale are tested in the State Key Laboratory of Ocean Engineering at Shanghai Jiao Tong University for the global performance of the spar hull, in which the second-order wave drift force is involved, as well as the effect of heave plates on the motion characteristics and mooring force of the G-spar platform.
