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*CDPOL, file=Filename

Data format:

One line with 2 parameters, as follows:

IGR ANG

Status:

Optional

Restriction:

A group must have been previously defined

Purpose:

To define a drag coefficient function of arc length and direction (in seawater).

Details :

Parameter	Description
IGR	Group number of the line
ANG	The reference angle in radian if the 0 of the coefficients does not correspond to the 0 of the beam orientation.
FILE=Filename	Path and name of the data file. The file format is the same as the file for hydrodynamic coefficients defined in *CDPOL, and is as shown below: Warning: - The file extension must be ".txt". - Angle values must be defined between 0 and 360 degrees.

    Number of angles
    List of angles  
    Curv. Ascissa 1     Cd at angle 1    ...     Cd at angle N  
    Curv. Ascissa 2     Cd at angle 1    ...     Cd at angle N  
    Curv. Ascissa 3     Cd at angle 1    ...     Cd at angle N  
    ...  
    Curv. Ascissa i     Cd at angle 1    ...     Cd at angle N

Data file example:

  2             ! number of angles  
  25 90         ! list of angles  
  0 1.0 1.0     ! Curv Absc  1/ Cd at angle 1 / Cd at angle 2  
  100   1.2   1.1  
  200   1.2   1.1  
  1000  1.2   1.1

Note

All angle values are in degrees. Note that the reference frame is the local vector (d1,d2) of each node where the drag is applied. The fluid- structure velocity direction (ang_fs) is evaluated in each location in the local frame. The angle is then used to interpolate the Cd using (ang_fs-ANG). Note that this option can be used with one angle to have a Cd function of arc length only.