Radiation Damping Coefficients |
 
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Radiation Damping Coefficients |
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The layout of the radiation damping terms is shown below and this can be repeated as often as necessary to define the radiation damping over a sufficiently large range of frequencies:
FREQ= Frequency
where:
•Frequency is the frequency value in Hz, to which the coefficients relate
•RD11 is the surge radiation damping at the relevant frequency
•RD22 is the sway radiation damping at the relevant frequency
•RD33 is the heave radiation damping at the relevant frequency
•RD44 is the roll radiation damping at the relevant frequency
•RD55 is the pitch radiation damping at the relevant frequency
•RD66 is the yaw radiation damping at the relevant frequency
and the remaining terms represent the radiation damping terms between various degrees of freedom at the relevant frequency.
The order of input specification is surge, sway, heave, roll, pitch, yaw. So the individual entries represent:
Units are as follows:
where:
•F are force units e.g. N, kN, lbf, kip
•M are moment units e.g. Nm, kNm, lbf.ft, kip.ft
•V are velocity units e.g. m/s, ft/s
•ω are rotational velocity units i.e. rad/s
•*RADIATION DAMPING is used to define radiation damping for a floating body.
If you would like to see an example of how this keyword is used in practice, refer to E02 - CALM Buoy - Complex.