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*CURRENTPOL,NAME = STRUCTURE_NAME

Data format:

One line comprising 4 parameters followed by an arbitrary number of line comprising 4 values each, as follows:

XC YC ZC SURFC ANGC(1) CXC(1) CYC(1) CMZC(1)
ANGC(2) CXC(2) CYC(2) CMZC(2)
...
ANGC(n) CXC(n) CYC(n) CMZC(n)

Status:

Optional

Purpose:

To define the hydrodynamic coefficients of the floating structure that yield current forces.

Restriction:

The current velocity is deduced from CURRENT and CURPROF at the current center of location of the floating body

Details :

Parameter Description
STRUCTURE_NAME Name of one of the mechanical structure in the hydrodynamic database. The name must include 8 characters maximum without any blank spaces.
XC X-Coordinates of the center of the current forces.
YC Y-Coordinates of the center of the current forces.
ZC Z-Coordinates of the center of the current forces.
SURFC Reference Sv surface for computing forces
ANGC(I) Value of the incidence (in degrees).
CXC(I) Hydrodynamic coefficient CXVI along OX
CYC(I) Hydrodynamic coefficient CYVI along OY
CMZC(I) Hydrodynamic moment coefficient CMZVI about OZ

Note

Coefficients must be entered for increasing values of the angle of incidence between 0 and 360 degrees., The relation between coefficient and loads is the following

\(F_{current} = \frac{1}{2} \rho S_v C_d V^2\)

where \(C_d\) is a drag coefficient, \(S_v\) the effective (or projected) surface in the current direction of the hull. The relation with the CXC values to input and the \(C_d\) values is :

\(CXC = \frac{S_v C_d}{S_ref}\)

Where \(S_ref\) is the constant reference surface given as input. The sign of the \(CXV\) coefficient defines the direction of the loads. For example, a current heading of 180 degrees (negative x-axis) provides a current loads directed towards x negative axis. The \(CXC\) coefficient has to be negative

Example:

*CURRENTPOL,NAME=FPSO
  0.    0.    10.   1000.
  1.    0.    0.    0.
  45.   1.14  1.14  0.2
  90.   0    -1     0.