Reply To: Hyrodynamic Response for Laying Barge

[Shuangxing Du]

(1) It is not necessary to define the super structure for wind drag calculation by Aqwa. Instead, please define the wind drag force/moment coefficients for all the possible directions from -180 degree to 180 degree.  If you really want to define the external surfaces of supper structure, it is OK, but please remove all the internal surfaces, especially between the upper deck and supper structures.

(2) If you want model the rigid pipeline by a mooring line, the boundary condition between mooring and laying barge/roller on the stinger cannot be modelled properly by Aqwa, as the ball/socket joint condition is applied at the fairlead point of the cable in Aqwa. 

(3) Not sure what you mean "the rigid pipeline". If it is rigid, you can define it by a structure with multiple tube elements. Then the supporting/constraining conditions between this "structure" and the laying barge/roller on the stinger can be defined by series of fenders.