Case 3.6

Conditions:

·        Bare hull with bilge keels

·        Towing condition in calm water

·        FRφ; s = 2.93×10-4, t = -3.47×10-2°

·        Re= 2.56×106, Fr=0.138, initial roll angle j= 10°

·        Wetted surface area at rest (S/L2) = 0.1476

Reference:

(3-4) Irvine, M., Longo, J., Stern, F. (2004), “Towing Tank Tests for Surface Combatant for Free Roll Decay and Coupled Pitch and Heave Motions,” Proc. 25th ONR Symposium on Naval Hydrodynamics, St Johns, Canada.

Instructions for Simulation: Simulation should be performed for SIX periods of the roll.

Table/

Figure #

Items

EFD Data

Submission Instructions

 

Data File

Image

Image File/Table

Sample

3.6-T

ERSS for force and moment coefficients and roll angle time history

Refer to sample file for details

Filename:            [Identifier]_T1_3-6.xls
                                        (Excel file)

IIHR-CFDShipV4_T1_3-6.xls

3.6-1

Time history of CTX

Ctx_EFD.dat

Ctx_EFD.lpk

EFD_CTX_3-6.jpg

 

(Dashed lines are plotted to shows the EFD trend)

Filename:        [Identifier]_CTX_3-6.jpg  

 

X-axis range:  1.0 ≤ t*L/U ≤ 2.0 (1 Flow time)

Y-axis range:    −0.075 ≤ CTX ≤ 0.075

                          

EFD: Open circle; CFD: Solid black line.

3.6-2

Time history of roll angle

Roll_EFD.dat

Roll_EFD.lpk

EFD_roll_3-6.jpg

Filename:           [Identifier]_Roll_3-6.jpg

 

X-axis range:  0 ≤ t*L/U ≤ 2.5

Y-axis range:    −10° j ≤ 10°

 

EFD: Open circle; CFD: Solid black line.

3.6-3

Mean wave-elevation ζ contours

z_mean_EFD.dat

z_mean_EFD.lpk

z_mean_EFD.jpg

Filename:         [Identifier]_z_mean_3-6.jpg

Axis:                   -0.1£ x £1.25; 0£ y £0.4

Contours levels:    -0.02 £ z/L £ 0.02, #levels = 11

Contour style:     Solid ( positive)  and broken

                                (negative) lines

3.6-4

Wave-elevation ζT contours during second cycle of roll decay: t/Te = 0, 1/4, 1/2, 3/4

z_0_EFD.dat

z_1-4_EFD.dat

z_1-2_EFD.dat

z_3-4_EFD.dat

 

z_0_EFD.lpk

z_1-4_EFD.lpk

z_1-2_EFD.lpk

z_3-4_EFD.lpk

z_0_EFD.jpg

z_1-4_EFD.jpg

z_1-2_EFD.jpg

z_3-4_EFD.jpg

Filename:         [Identifier]_z_0_3-6.jpg

                            [Identifier]_z_1-4_3-6.jpg

                            [Identifier]_z_1-2_3-6.jpg

                            [Identifier]_z_3-4_3-6.jpg

Axis:                   -0.1£ x £1.25; 0£ y £0.4

Contours levels:    -0.02 £ z/L £ 0.02, #levels = 11

Contour style:    Solid ( positive)  and broken

                                  (negative) lines

 

3.6-5

Contours of U velocity at x/LPP=0.675 during second cycle of roll decay: t/Te = 0, 1/4, 1/2, 3/4

u_0_EFD.dat

u_1-4_EFD.dat

u_1-2_EFD.dat

u_3-4_EFD.dat

 

u_0_EFD.lpk

u_1-4_EFD.lpk

u_1-2_EFD.lpk

u_3-4_EFD.lpk

u_0_EFD.jpg

u_1-4_EFD.jpg

u_1-2_EFD.jpg

u_3-4_EFD.jpg

Filename:         [Identifier]_U_0_3-6.jpg

                            [Identifier]_U_1-4_3-6.jpg

                            [Identifier]_U_1-2_3-6.jpg

                            [Identifier]_U_3-4_3-6.jpg

Axis:                    -0.065£ x £-0.03; -0.055£ y £-0.01

Contours levels:    0.7 £ U £ 1.0, #levels = 11

Contour style:       Solid lines

 

3.6-6

Contours of V velocity at x/LPP=0.675 during second cycle of roll decay: t/Te = 0, 1/4, 1/2, 3/4

v_0_EFD.dat

v_1-4_EFD.dat

v_1-2_EFD.dat

v_3-4_EFD.dat

 

v_0_EFD.lpk

v_1-4_EFD.lpk

v_1-2_EFD.lpk

v_3-4_EFD.lpk

v_0_EFD.jpg

v_1-4_EFD.jpg

v_1-2_EFD.jpg

v_3-4_EFD.jpg

Filename:           [Identifier]_V_0_3-6.jpg

                              [Identifier]_V_1-4_3-6.jpg

                              [Identifier]_V_1-2_3-6.jpg

                              [Identifier]_V_3-4_3-6.jpg

Axis:                     -0.065£ x £-0.03; -0.055£ y £-0.01

Contours levels:    -0.15 £ V £ 0.1, #levels = 11

Contour style:       Solid ( positive)  and broken

                                  (negative) lines

 

3.6-7

Contours of W velocity at x/LPP=0.675 during second cycle of roll decay: t/Te = 0, 1/4, 1/2, 3/4

w_0_EFD.dat

w_1-4_EFD.dat

w_1-2_EFD.dat

w_3-4_EFD.dat

 

w_0_EFD.lpk

w_1-4_EFD.lpk

w_1-2_EFD.lpk

w_3-4_EFD.lpk

w_0_EFD.jpg

w_1-4_EFD.jpg

w_1-2_EFD.jpg

w_3-4_EFD.jpg

Filename:           [Identifier]_W_0_3-6.jpg

                              [Identifier]_W_1-4_3-6.jpg

                              [Identifier]_W_1-2_3-6.jpg

                              [Identifier]_W_3-4_3-6.jpg

Axis:                     -0.065£ x £-0.03; -0.055£ y £-0.01

Contours levels:    -0.1 £ W £ 0.14, #levels = 11

Contour style:      Solid ( positive)  and broken

                                (negative) lines

 

Hull data at x/LPP=0.675 during second cycle of roll decay: t/Te = 0, 1/4, 1/2, 3/4

(for plotting EFD data in Figs. 3.6-5, 6 and 7)

T_0_Hull.dat (t/Te = 0)

T_1-4_Hull.dat (t/Te = 1/4)

T_1-2_Hull.dat (t/Te = 1/2)

T_3-4_Hull.dat (t/Te = 3/4)

 

*[Identifier] should be [Institute Name]-[Solver Name]. For example, if your institute is IIHR and solver is CFDShip-Iowa V.4, identifier should be IIHR-CFDShipV4.

All figures have aspect ratio of 1:1.

 

·                  CFD predicted force coefficients should be reported using the wetted surface area at rest ( S/L2).

·                , where FX is the total resistance.