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*WVANING
Data format:
A maximum of 3 lines as follows:
NREF NFPF NODFAIR NNOD NGR IOP YAW CRIT
NOD1 IOD2 ...
NGR1 NGR2 ...
Status :
Optional
Restriction :
Nodes and groups of elements must have been previously defined.
Purpose :
To compute the equilibrium a a floater under environmental mean loading and given a connection point. If the connection is defined by a line, it is also possible to obtain the line orientation. Then, before the static calculations are started, the floater (and possibly connexion lines) are oriented in this equilibrium position considered as an initial position. This reduces the lengthy transitory phase to approcah the equilibrium position in dynamic.
Details:
| Parameter | Description |
|---|---|
| NREF | Reference Node to perform the rotation of the system (e.g. turret center) |
| NFPF | Floaters Center of Motion (Equilibrium calculations performed on that floater) |
| NODFAIR | Fairlead of the floater : Point where the environmental forces are counteracted by the hawsers/mooring of the floater |
| NNOD | Number of Nodes to be rotated around the reference node |
| NGR | Number of Groups in which all nodes of the group are rotated around the reference node |
| IOP | IOP = 0 : This option rotates the floater by YAW around around point (NODFAIR). The reference node (turret) is connected to the floater defined by NFPF (and not to another floater). It is similar to option 2 but with yaw imposed instead of computed IOP = 1 : This option computes one equilibrium position of the floater in yaw due to environmental force and considering that the floater is connected at one point (NODFAIR). It also provide the direction of the environmental loads. The floater is rotated incrementaly over 360 to find the equilibrium position:  This provides the equilibrium angle for the floater, the environmental force provides the angle for the mooring 2 This option computes one equilibrium position of the floater in yaw due to environmental force and considering that the floater is connected at one point (NODFAIR). The reference node (turret) is connected to the floater defined by NFPF (and not to another floater). The same equilibrium calculation is performed for the floater equilibrium as in IOP=1. This time there is no hawser, the turret is directly connected to the floater. The turret orientation is not changed before static analysis, only the floater is rotated. |
| YAW | Value of yaw to be imposed on the floater with option 0 (degrees) |
| CRIT | The value must be between 0 and 1. By default, CRIT = 0. If two equilibrium are found, the one with the largest moment gradient is selected (CRIT=0). It is also possible to select the equilibrium which has the largest angle range of stability (CRIT=0). For any other value of CRIT between 0 and 1 the most stable equilibrium will be chosen as a mixed of the two criteria based on the weight CRIT |
| NOD1 IOD2 ... | If NNOD > 0, extra line to provide the node numbers |
| NGR1 NGR2 ... | If NGR > 0, extra line to provide the group number |
