*VIMPOL

Data format:

One line with 2 values followed by an arbitrary number of lines with 3 values each.

NODE_FPF IDDL
ANG(1) CL_CR(1) Cl_IN(1)
...
ANG(n) CL-CR(n) Cl_IN(1)

Status :

Optional

Purpose :

This keyword allows to prescribe in-line and cross-flow lift coefficients as a function of direction within the Van der Pol oscillator model and has applications to predict vortex induced motions.

Restrictions :

If VIMPOL is defined, a FPFDX is required to define the master node of the floater. A *VDP is also required to define the Van der Pol parameters, and the group of elements on which the flui forcing is applied. This group must be linked to the floater fairleads by the user.

Details :

Parameter	Description
NODE_FPF	corresponds to a master node of a FPFDX. Note that if a VIM analysis is requested, no hydrodynamic database is read, even if the FPFDX is linked to a hydrodynamic database file.
IDDL	new degrees of freedom of the floater for VIM analysis (generally 001111)
ANG(i), CL(i), CLIN(i)	table giving the cross-flow and inline lift coefficients as a function of angle (it the angle between the current direction and the floater axis). If the third column is omitted, there is no inline forcing. Cross-flow and inline are defined with respect to the current direction.