|
Figure 8 Turning trajectories and time histories of parameters
Ship A
Ship B
Table 1 Coefficients of correlation of simplified estimation equation
| Index |
ψ1(10) |
ψ2(10) |
ψ1(20) |
ST |
AD |
DT |
| b0 |
109.824 |
129.985 |
54.325 |
-0.425 |
6.288 |
0.356 |
| b1 |
6.865 |
-14.023 |
-1.063 |
-0.456 |
0.112 |
1.761 |
| b2 |
-119.877 |
-160.810 |
-59.357 |
4.958 |
0.290 |
1.185 |
| b3 |
4.466 |
-14.474 |
-13.994 |
1.152 |
4.096 |
-2.599 |
| b4 |
-76.321 |
-63.442 |
-24.287 |
1.638 |
- |
- |
| b5 |
197.039 |
127.863 |
27.173 |
-5,719 |
- |
- |
|
where, b0 - b5 are coefficients which have different values for each performance index as shown in Table 1. They had defined by the sea trial data in manoeuvring performance data base [21], σa is the same coefficient as shown in equation (7). The hydrodynamic derivatives Y'v, Y'r, N'v & N'r in equation (10) is calculated by Inoue's approximate formulae [22]. Δ, γ & l'R are given by,
γ is a flow straightening coefficient and l'R is a experimental coefficient. aγ, aτ0 & aτ1) are given by experimental results. Besides, aH is an interaction coefficient between rudder and a ship hull and FN is a normal force of rudder.
|
