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Modern Windships; Phase 2

Appendix 5. Calculation of Ship Motions and Accelerations

According to DNV, Volume 1, Pt. 3, Ch. 1, Sec. 4

Ship design factors given from the ship designers:
Surge, sway/yaw and heave accelerations: {B300}
Roll motion and acceleration: {B400}
Pitch motion and acceleration: {B500}
Combined vertical acceleration: {B600}
Combined transverse acceleration: {B700}
Combined longitudinal acceleration: {B800}
Combination between acceleration in different directions
Vertical and transverse force: {C500}
Vertical and longitudinal force:

Ship design factors given from the ship designers:

L=210 m
V=16 knots
D=19 m
T=12 m
CB=0.738
k=1.2

Surge, sway/yaw and heave accelerations: {B300}

The surge acceleration is given by:

The combined sway/yaw acceleration is given by:

The heave acceleration is given by:

Roll motion and acceleration: {B400}

Roll angle is given by:

The period of roll is given by:

z = distance from the baseline to the roll axis of rotation

The tangential roll acceleration at the height, h above the baseline is given by:

Pitch motion and acceleration: {B500}

Pitch angle is given by:

The period of pitch is given by:

The tangential pitch acceleration at the length, l from the A.P. is given by:

Combined vertical acceleration: {B600}

Combined transverse acceleration: {B700}

Since we want to have ary given as an angular acceleration and ay is small compared to the other terms, the transverse acceleration is calculated as:

Forsat

Combined longitudinal acceleration: {B800}

Forsat

Combination between acceleration in different directions

Vertical and transverse force: {C500}

Vertical force:

Transverse force:
Forsat

Vertical and longitudinal force:

Vertical force:

Longitudinal force:

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