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### Damping data

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In this tab a damping file can be imported. A damping file contains=
linear and quadratic damping coefficients for six degrees of freedom. Thes=
e coefficients are put at the main diagonal of the damping matrices; o=
ff-diagonal terms are not applied in aNyMOOR. The damping coeffic=
ients can be the results of decay tests, for example. Using a damping file =
is not obligatory.

The file should contain two columns, separated by spa=
ces and/or tabs. The first column contains linear damping coefficients for =
all 6 degrees of freedom, the second column contains quadratic damping coef=
ficients. The units of the linear damping coefficients are [kN/m/s] and [kN=
m/rad/s], the units of the quadratic coefficients are [kN/(m/s)^{2}=
] and [kNm/(rad/s)^{2}]. Here is an example showing linear dampi=
ng for surge, sway, roll and yaw.

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Next, the following check boxes are available:

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- Scale damping file
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- Wichers damping
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- Use Aranha approximation

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#### Scale damping file

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When a damping file is available this damping data can be scal=
ed with the scale factor from the Ship data tab. This is done when the=
check box "Scale damping file" is selected. The scale factors can be found=
in the table above.

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#### Wichers damping

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The so-called Wichers damping is applied when the check box "Wichers dam=
ping" is selected. This is a calculation method for viscous damping, with a=
nd without current, for tanker shaped vessels. When selected the "Rel=
ative loading condition" should be given. This is the actual draft of the v=
essel as percentage of the maximum draft. The value should be in the range =
40..100 %.

More information can be found in the PhD thesis "Simulat=
ion model for a single point moored tanker" by J.E.W. Wichers.

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#### Use Aranha approximation

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The Aranha method is applied for the correction of wave drift forces due=
to current. It has two additional properties which can be selected:

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- Check box "Without current": use Aranha without taking current into acc=
ount
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- Check box "Newman correction on P-matrix": use Aranha with the Newman c=
orrection on the P-matrix

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More information about the Aranha damping can be found in a pdf-file.

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