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4.4 Added Masses and Moments
Added mass of the hull along x axis, m*, was assumed as the value of spheroid [7]. Since the frequency of swaying and yawing motion is very low, my and Jzz)are calculated with the double model expressed by the Lewis form coefficient, Cl and C3, as follows:
Values of mz and Jyy are also calculated as follows:
We assumed Jxx was 30% of lxx for the hull excluding the mast and yard. Added mass of the huge rudder along y axis was calculated assuming it as an cllipsoid plane, and included in the values of my and Jzz The values of these added masses and moments are shown in Table 3 with inertia forces and moments of the ship. It should be noticed that the masses of the mast and yard severely affects on the values of lxx and lyy.
Table 3 Added masses and moments of inertia of ship
| m |
147.0×103 |
kg |
| mx |
4.4×103 |
|
| my |
109.6×103 |
|
| mz |
301.8×103 |
|
|
| |
Kg・m2 |
|
kg・m2 |
| Ixx |
1799×103 |
Jxx |
226×103 |
| Iyy |
5786×103 |
Jyy |
8268×103 |
| Izz |
4741×103 |
Jzz |
4602×103 |
|
4.5 Aerodynamic Coefficients of Sail
Figure 9 shows the aerodynamic coefficients of sail obtained by the wind tunnel tests in the reference [1]. It should be noted that these data indicate at the maximum thrust condition of the sail. Ks' is assumed as follow:
where Zcp is z-coordinate of the center of pressure of sail.
Fig.9 Aerodynamic coefficients of sail
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