Nomoto K - Turning-Rate Gain
Nomoto first-order K index from turning-circle steady-state rate of turn - a compact ship-handling metric used in IMO zig-zag and turning tests.
K index
0.04501/s
Formula, assumptions, and limits
$$K = \dot\psi_{ss} / \delta_R$$
Higher K = more responsive rudder. Typical value 0.1–0.2 1/s for merchant ships. Combine with T to form first-order turning model.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $\dot\psi_{ss}$ | Steady yaw rate | rad/s | zig-zag / turning |
| $\delta_R$ | Applied rudder angle | rad | helm order |
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