Dear Jason,
The thread above relates to a symmetrical floating platform. I am investigating the feasibility of representating an assymmetric platform in FAST.
We are considering building a model of a wind turbine on a floating platform in which the tower interace is offset horizontally from both the platform centre of mass and the centre of buoyancy. I would like to evaluate the changes we would need to make to FAST in order to take account of this offset.
In FAST.F90, Line 5130, the position vector rZY of the platform mass centre (point Y) with respect to the platform reference point (Point Z), is calculated as a scalar. I presume that is because you have assumed that both points lie on the centreline of the tower and sub-structure (the whole support structure is uni-dimensional and axisymmetric). Also on Line 5518, the velocity of the platform mass centre is calculated using the cross product of the angular velocity and rZY. I assume that a2 is defined as the unit vector, [0,0,1].
Can you foresee any problems if rZY is redefined as [rZYxt, rZYyt, rZYzt] so that there is an additional arbitrary horizontal offset of the mass centre [rZYxt, rZYyt, 0]?
Many thanks.
Kind Regards,
Mark