Case 1.4a

Conditions:

· Without rudder

· Towing condition in head waves

· FR_zθ

· Re = 2.55×10⁶, Fr = 0.142

· Wave height= 60mm

· Three wave lengths

No.	1	2	3
λ/LPP	0.6	1.1	1.6

References:

Not yet available.

Instructions for Simulation: Simulation should be performed for THREE periods of the incoming wave.

Table/ Figure #	Items	EFD Data		Submission Instructions
		Data File	Image	Table/Image File	Sample
1.4a-1	Comparison of 0th and 1st harmonic amplitudes and 1st harmonic phase of the total resistance coefficient (CT), heave motion (z) and pitch angle (θ)	Refer to sample file for details		Filename: [Identifier]_3waves_1-4a.xls  (Excel file)	[Identifier]_3waves_1-4a.xls
1.4a-C1	Time histories of total resistance coefficient (CT), heave motion (z) and pitch angle (θ) (λ/LPP=0.6)	Not yet available	Not yet available	Filename: [Identifier]_CT1_1-4a.jpg ( for CT ) [Identifier]_z1_1.4a.jpg ( for z ) [Identifier]_theta1_1-4a.jpg ( for θ ) X-axis range:  0.0 ≤ t/T ≤ 3.0 Y-axis range: to be added Style:    CFD solid line EFD open circles Δ(t/T) = 0.05	Not yet available
1.4a-C2	Time histories of total resistance coefficient (CT), heave motion (z) and pitch angle (θ) (λ/LPP=1.1)	Not yet available	Not yet available	Filename: [Identifier]_CT2_1-4a.jpg ( for CT ) [Identifier]_z2_1.4a.jpg ( for z ) [Identifier]_theta2_1-4a.jpg ( for θ ) X-axis range:  0.0 ≤ t/T ≤ 3.0 Y-axis range: to be added Style:    CFD solid line EFD open circles Δ(t/T) = 0.05	Not yet available
1.4a-C3	Time histories of total resistance coefficient (CT), heave motion (z) and pitch angle (θ) (λ/LPP=1.6)	Not yet available	Not yet available	Filename: [Identifier]_CT3_1-4a.jpg ( for CT ) [Identifier]_z3_1.4a.jpg ( for z ) [Identifier]_theta3_1-4a.jpg ( for θ ) X-axis range:  0.0 ≤ t/T ≤ 3.0 Y-axis range: to be added Style:    CFD solid line EFD open circles Δ(t/T) = 0.05	Not yet available

Note: a positive (+) heave value is defined upwards and a positive (+) pitch value is defined bow up.

Submission Instructions: 

· Filename: [Identifier]_3waves_1-4a.xls   (Excel file)

· [Identifier] should be [Institute Name]-[Solver Name]. For example, if your institute is Chalmers and solver is SHIPFLOW4.2, identifier should be Chalmers-SHIPFLOW4.2

Identifier in the Figure should be [Institute Name]/[Solver Name]. For example, if your institute is Chalmers and solver is SHIPFLOW4.2, identifier should be Chalmers/SHIPFLOW4.2

· Sample files:         Chalmers-SHIPFLOW4.2_3waves_1-4a.xls

· All figures should have aspect ratio of 1:1

Remarks:

· Coordinate system for comparisons is fixed to x=0.0 (FP) on the undisturbed water plane.

· The center of the pitching moment is same as the center of gravity.

· All CFD predicted force coefficients should be reported using the wetted surface area at rest ( S₀/L² ). Force coefficients are defined as follows:

where is the total resistance.

· Symbols:

- Incident wave amplitude

- Wave steepness,

- Frequency of the incident wave,

- Encounter frequency,

- Encounter period,

- Time, at t=0 a crest of the incident wave is coincident with the FP of the ship

- Ship speed

- Velocity components in directions, respectively

- Incident wave length

- Free surface elevation,

· Instructions:

As a time reference, incident wave height at FP of the ship is defined as

where is the initial phase and is equal to be zero from the present definition of above.
Fourier Series for time history are determined as follows:

is n-th harmonic amplitude and is the corresponding phase.