Investigation on Hydrodynamic Performance of T ...

船舶力学

第 17 卷第 12 期 2013 年 12 月

Journal of Ship Mechanics

Vol.17 No.12 Dec. 2013

Article ID ： 1007-7294 （2013 ）12-1426-13

Investigation on Hydrodynamic Performance of T-shaped Barge in Topside Transportation XU Xin, YANG Jian-min, LI Xin, LU Hai-ning (State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)

Abstract: T-shaped barge is a new concept in floatover transportation and installation in order to satisfy both the breadth limit of platform slot and transverse stability requirement. It has some char鄄 acteristics different from conventional barges. In this paper, comparisons of hydrodynamic perfor鄄 mance between T -shaped barge and conventional barge are performed in frequency and time do鄄 main. Motion RAOs (response amplitude operator) and drift forces are obtained using the code WAMIT in frequency domain. Besides, motion series and statistics in irregular waves are calculated in time domain by a self-compiled program with FORTRAN code. Corresponding model tests are also carried out to verify the numerical results and it turns out that the test results agree quite well with numerical computation. Comparisons between T-shaped barge and conventional barge show that Tshaped barge has better hydrodynamic performance in topside transportation. Key words: floatover; T-shaped barge; marine transport; hydrodynamic performance CLC number: U661.32 Document code: A doi: 10.3969/j.issn.1007-7294.2013.12.007

1 Introduction Topside installation of platform in open waters has always been a great challenge for off鄄 shore operation. Floatover is a new method to install the integrated topside onto a platform with some substantial advantages, such as high capacity, short project time and low costs[1-2]. In this method, the topside is constructed as one large integrated module and assembled completely on shore, then is transported by a barge to installation site, and finally transferred from the trans鄄 portation barge onto the supporting structure through barge ballasting as shown as Fig.1(a)[3-4]. So far over thirty floatover installations have been carried out successfully in open wa鄄 ters, and the largest topside weighted over 20 000 tons[5]. As the topside is becoming increas鄄 ingly heavier, the installation barge is in need of larger displacement and breadth to increase the lifting capacity needed, while the barge breadth is also limited to the size of jacket slot. Thus a T-shaped barge concept is put forward to eliminate this limit by its narrower bow half and its wider stern half which contributes to a larger displacement and a better transverse sta鄄 bility (Fig.1(b)). Consequently, it allows the vertical COG (center of gravity) of the transported Received date: 2013-06-17 Foundation item: Supported by the Youth Innovation Fund of State Key Laboratory of Ocean Engineering (No.GKZD010059-21) Biography: XU Xin(1988-), male, Ph.D. student of Shanghai Jiao Tong University, E-mail: [email protected]; YANG Jian-min(1958-), male, Professor/tutor, E-mail: [email protected].

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topside to be higher above the barge deck, which permits a larger air gap for easier and safer installation. For example, a special T-Shaped Barge TCB-2 (Fig.1(c)) was purpose-built to in 鄄 stall the 21 800Te Lunskoye-A (Lun-A) Topsides and it broke the original world record of the heaviest topside in June 2006[6].

(b) Topside transport in waves (c) T-shaped barge (a) Floatover for a jacket Fig.1 Floatover installation using a T-Shaped Barge

The T -shaped barge has some unique characteristics different from conventional barge which has the same breadth at bow and stern. The topside transportation is concerned by many designers in that the high COG of the system leads to large motion responses especially in roll mode. In order to investigate hydrodynamic performance of the T-shaped barge, numeri 鄄 cal simulations are carried out for two T-shaped barges and a conventional barge. Data from model tests performed at SKLOE (State Key Lab of Ocean Engineering, Shanghai Jiao Tong U鄄 niversity, China) is also presented to verify the numerical result.

2 Mathematical formulation 2.1 Hydrodynamic analysis in frequency domain Assuming the incompressible and inviscid flow with irrotational motion, the velocity po 鄄 tential 椎 is introduced, which satisfies the Laplace equation within the fluid domain. The gov鄄 erning equation and linearized boundary conditions which are satisfied by the diffraction and radiation potentials 准m (m=D or j, j=1~6) are summarized as follows[7]: 2

荦准m=0 in the fluid domain 2 -棕准m+g 坠准m=0 on the mean water surface 坠z 坠准 =0 on the Seabed 坠n m 坠准D 坠准 =- I on body wet surface for diffraction potential 坠n 坠n 坠准 =n 荦 j=1,2,… ,6 荦on body wet surface for radiation potential 坠n j j

(1) (2) (3) (4) (5)

where 准 I is the incident wave potential; 棕 is the wave frequency; the unit vector 軋n is normal to the body boundary and points out of the fluid domain.

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The boundary -value problem of first order in the wave amplitude can be derived and solved, and the details can be found in previous research [7-10]. Based on the diffraction pressure field, the linearized hydrodynamic forces (and moments) acting on the body are represented as follows: Fi =-i棕籽

蓦准 n dS SB

D

(6)

i

where Fi is the wave exciting force in the i-th mode of motion of the body. Based on the radi鄄 ation field, the added mass Ai j and damping coefficient Bi j in the i-th direction due to the jth mode of motion can be written as Ai j - 蓦 Bi j =籽 i/棕蓦

蓦准 n dS j

SB

(7)

i

The 2nd order mean drift forces and moments can be calculated from the first-order lin 鄄 ear potential. There are two alternatives available including near field method [11] (direct pres鄄 sure integration of the pressure on the body surface) and far field method (application of mo 鄄 mentum theorem)[12-13]. The present study is based on far field method. The horizontal drift forces and vertical moments are evaluated from the following expressions, 3

蓦 2蓦 c Fx = 籽g淄 2 p 8仔棕 2cg

3

乙 2蓦 c Fy = 籽g淄 2 p 8仔棕 2cg

3

2仔

乙 0

2仔

乙 0

c Mz = 籽g淄 2 p Im 8仔棕 2cg 乙 2蓦

H 乙蓦兹 cos兹d兹- 籽gA淄 cos 茁ImH′ 乙仔+茁蓦 2棕 2

H 乙蓦兹 sin兹d兹- 籽gA淄 sin 茁ImH′ 乙仔+茁蓦 2棕 2

2仔

(8)

兹 H′ 乙蓦兹 d兹- 籽gA淄 ReH′ 乙茁蓦乙 H 乙蓦 2棕 *

0

*

where cp is the phase velocity, cg is the group velocity, H denotes the complex conjugate, H′ denotes the derivative of the Kochin function, and H 乙蓦兹 =

蓦

Sm

2

乙准Bn准I-准B 准In 蓦 dS,

cp kh = , k= 棕 2 2 2cg kh+ 乙 g 淄h 蓦- 乙 kh 蓦

where, 准B =准D+准R is the part of the total potential due to bodies. 2.2 Motion equation in frequency domain The equation of the rigid body motions of 6 DOF (degree of freedom) in frequency domain can be expressed as 乙 Mi j +Ai j 乙棕蓦乙孜咬 j+Di j 蓦孜觶 j+Ki j 孜j =Fi 蓦棕蓦棕蓦蓦 i=1~6 蓦

(9)

where, Mi j is inertia matrix; Ai j is added mass matrix; Di j is potential damping matrix; Ki j is restoring coefficient matrix; Fi is first order wave force and moment; 孜j is vector containing the three translational and three rotational displacements about the coordinate axes in j-mode. The first order motion RAO (response amplitude operator) can be expressed as: RAO 蓦 =孜蓦 =乙棕蓦棕蓦 M+A 蓦 -i棕D+K -棕乙棕蓦乙 2

-1

乙 F 蓦棕蓦

(10)

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2.3 Motion equation in time domain Based on Newton ’s second law, the 6-DOF non-linear motion equations for a rigid body with respective to COG can be expressed as: M+A x咬 t +Dx觶 t +Kx t =f t 1

(11)

2

f= fwave+fwave+fwind+fcurrent+fext where f t are the external force and moment vector including 1st order wave exciting force, 2nd wave drift force, wind force, drag force and other connecting forces. Assuming linear behavior of wave effects and considering impulses in the components of motion, the motion equation of a floating body can be written as [14] t

M+A ∞

x咬 t +

乙R t-子

x觶子 d子+Kx t =f t

(12)

-∞

where, the convolution terms capture the effect that the changes in momentum of the fluid at a particular time affect the motion at subsequent time, which is known as fluid memory effect. R t is the retardation function which depends on the geometry of the body, and can be cal鄄 culated by added mass and damping coefficient as follows: ∞

乙

∞

乙

D 棕 cos棕td棕=- 2 棕 A 棕 -A ∞ cos棕td棕 (13) R t =2 仔 0 仔 0 All the coefficient matrixes in Eq.12 can be obtained in frequency domain analysis. In the numerical simulation, the fourth order Runge-Kutta method is used for the numer 鄄 ical integration of motion equation (Eq.12) which is a second order ordinary differential equa 鄄 tion, and the formula and code detail can be found in the Refs.[15-16].

3 Numerical simulation 3.1 Description of T-shaped barge transportation system The transportation system contains a T-shaped barge, topside and a DSF (deck support frame) with 10 DSU (deck support units). The topside is supported by DSF which is used to distribute highly concentrated topside leg loads onto the barge frames. The barge is 215 m in length, 14.25 m in depth, and the width of the bow half is 42 m, while the stern half is 65m. Fig.2 and Fig.3 show the right side view and the top view of the transportation system. The main

Fig.2 The right side view of barge with topside

Fig.3 The top view of barge with topside

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particulars of the barge and topside are listed in Tab.1. In the transportation configuration, the topside is fixed on the barge by welding, so the whole system can be regarded as a rigid body. Tab.1 Main particulars of transportation barge system Unit

Barge

Topside

Draft at bow

m

7.5

—

Draft at stern

m

8.0

—

Displacement

Description

tons

62 565.5

27 000

LCG (from barge stern)

m

74.79

134.99

VCG (from barge keel)

m

7.35

42.97

Radius of roll gyration

m

18.97

28.1

Radius of pitch gyration

m

64.02

39.8

Radius of yaw gyration

m

65.08

45.1

3.2 Hydrodynamic model of barges In order to investigate the unique character of T-shaped barge, we study three different barges including one conventional barge and two T-shaped barges. As shown as Fig.4, barge3 is the T-shaped barge described above; barge-2 is also a T-shaped barge with 42 m bow breadth (same with barge-3) and 52.5 m stern; barge-1 is a conventional barge with 52.5 m breadth. Fig.5 shows the panel models of these three barges and they are meshed with 2 450, 2 020 and 1 796 elements respectively. We adopt the same draft for these three barges for ease of hydrodynamic performance comparison in frequency domain analysis. Barge-3

Barge-1

Barge-2

Fig.4 The top view of three barge contours

(a) Barge-1

(b) Barge-2 Fig.5 The panel models of three barges

(c) Barge-3

Numerical simulation in frequency domain was carried out by commercial code WAMIT, which is developed by MIT. Velocity potential on each element was solved, and hydrodynamic parameters in frequency domain were calculated. 3.3 Environment condition In our research, the water depth of the location is 200 m. Since we concern the seakeeping

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of the barge due to wave effect, this simulation only considers the waves without wind and cur鄄 rent. The irregular wave spectrum is Pierson -Moskowitz (PM) spectrum, and the expression can be written as[17], 2

-4

-5

-4

S !" f =琢Hs Tp f exp # Tp f " -1.25 !

$

(14)

where, S !" f is spectral wave energy density distribution, Hs is significant wave height, f is wave frequency, fp=1/Tp is peak wave frequency, Tp is period of peak wave spectral density, and 琢= 0.2. To validate the numerical simulation, calculation and model test were carried out for one irregular wave condition, in which H s is 5.4 m and Tp is 13.5 s for 180 deg, 135 deg and 90 deg in direction, respectively. The time domain simulation was carried out by solving Eq.12 using a self-compiled program written by FORTRAN.

4 Model test A series of model tests were carried out in the State Key Laboratory of Ocean Engineer鄄 ing (SKLOE) basin. The scaling factor is 1:50, and the water depth of model scale is 3.8 m. The barge is moored by 4 wire-springs (2 wiresprings attached at fore and aft locations, re鄄 spectively) as shown in Fig.6, which is used to withstand wave drift force. The tests included decay tests, white noise wave tests and irregular wave tests. Decay tests Fig.6 The arrangement of barge model were performed in still water in roll and pitch in the basin mode to validate the moment of inertia. In white noise wave tests, the response amplitude op 鄄 erator (RAO) was obtained by means of spectral analysis for motion results. In the irregular

Wave (m2s/rad)

Measured Target

ω (rad/s)

Fig.7 The irregular wave test in the beam sea condition

Fig.8 Comparison between measured and target wave spectrum

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wave tests, the sea states in three wave directions were generated by a PM spectrum with sig 鄄 nificant wave height of 5.4 m and peak period of 13.5 s. Fig.7 shows the irregular wave test in the beam sea condition. Wave probes of resistance type at specified locations provided mea 鄄 surements of generated wave elevation. For each irregular wave case, the maximum wave ele 鄄 vation above mean water surface was 0.97 to 1.03 times the target significant wave height. As Hs " shown in Fig.8, the spectra generated in the basin presented that significant wave height ! Tp "are within plus or minus 5% of the target values, which are listed in and peak period ! Tab.2. The effective duration for each irregular wave was over 3 hours in full scale (25.5 mins in model scale). Tab.2 The comparison between measured and target wave spectrum parameters Parameter

Symbol

Unit

Measured

Target

Hs

m

5.33

5.40

Zero-crossing wave period

Tz

s

10.68

10.55

Period of peak wave spectral density

Tp

s

13.69

13.50

Peak frequency

fp

rad/s

0.46

0.46

m2s/rad

5.59

5.67

Significant wave height

Peak value

5 Results and discussion 5.1 Frequency domain analysis results 5.1.1 Calculation VS. model test In order to validate the numerical models and the first order boundary value problem so 鄄 lution in frequency domain, a comparison of RAOs between calculation and experiment is car鄄 ried out first. Fig.9 shows 6-DOF motion RAOs in head sea and beam sea condition, and fairly good agreements are obtained for each motion mode except for some discrepancy at narrow band frequencies near the natural frequency for some mode. As shown in Fig.9 (b) and (d), there is a little difference at around the frequency of 0.7 rad/s (the natural frequency of pitch) in the head sea, which is because that the barge motion is large and nonlinear at the natural frequency, and the linearization of RAOs underestimates the motion. As shown in Fig.9(c), the peak of roll RAO occurs at the frequency of 0.4 rad/s, and its magnitude continues to decrease

(a) Surge and sway motion

(b) Heave motion

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(c) Roll motion (d) Pitch motion Fig.9 The comparison of RAOs between calculation and experiment

with the additional damping increasing. The solid diamond points present the experimental re 鄄 sult, which is less than the calculation value around natural frequency when no viscous damp鄄 ing was considered. When the linearized roll damping(D44) equals 1.0E9 N/(deg/s) 2 or critical damping(CD) equals 0.01, the calculation result is consistent with model test. 5.1.2 Comparisons between different barges In order to compare hydrodynamic characteristics between T-shaped barge and conven 鄄 tional barge, 1st and 2nd order wave forces of one conventional barge and two T-shaped barges are calculated in frequency domain. Fig.10 shows the comparison of 1st order wave exciting moment in the roll and pitch mode among three barges. The roll moment of Barge-3 is larger than that of Barge-1 and Barge-2 in beam sea at the natural frequency, as shown in Fig.10(a), but it is smaller than that of Barge-1 and Barge-2 when wave frequency is larger than 0.7 rad/s (wave period is smaller than 9s), which means Barge-3 has smaller roll moment response in majority sea conditions. As shown in Fig.10(b), the pitch moment of Barge-1 is nearly zero at beam sea because of the longitudinal symmetry, while Barge-3 has a larger moment due to the different breadths at bow and stern; the pitch moment of Barge-3 in head sea is larger than that in following sea.

(a) Roll moment (b) Pitch moment Fig.10 The comparison of 1st order wave exciting moment among three barges

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As shown in Fig.11(a), the longitudinal drift forces of Barge-1 in head sea and following sea are approximate, but the longitudinal drift forces of Barge-3 in following sea are nearly two times of that in head sea. Fig.11(b) shows that the three barges have similar transverse drift force in beam sea. The results of horizontal drift moment are shown in Fig.11(c) and it can be seen that T-shaped barge has a larger moment at 45deg wave heading.

(a) Absolute value of longitudinal drift force

(b) Transverse drift force

(c) Horizontal drift moment Fig.11 The comparison of 2nd order wave drift force and moment among three barges

5.2 Time domain analysis results 5.2.1 Calculation VS. model test The time domain simulation can be carried out once the frequency domain results have been derived. We compare the free decay test results with calculation results in order to vali 鄄 date the numerical program and to verify the adjustment of COG and gyration radius in model test. Fig.12(a) and (b) shows roll and pitch free decay comparisons. The prediction results a 鄄 gree well with the model tests. We can find the natural period of roll motion is nearly 16 s and corresponding frequency is 0.393 rad/s, which is consistent with RAO result. Furthermore, the roll viscous damping is also proven indispensable to roll motion. For the pitch decay, the nat 鄄 ural period is nearly 9.5 s and corresponding frequency is 0.67 rad/s, which agrees well with frequency domain analysis.

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(a) Roll decay (b) Pitch decay Fig.12 The comparison of decay test between calculation and experiment

The comparison of motion response in irregular wave condition is executed between time domain simulation and model test. The wave condition is given by a PM spectrum with signifi鄄 cant wave height of 5.4 m, peak period of 13.5 sec, and the direction includes 180, 135 and 90deg. The wave frequency motions (heave, roll and pitch) are concerned in the transportation condition. Tab.3 lists the comparison of all statistic results between the model test and analysis in three wave directions. Most of the calculation results are in agreement with the model test except the roll motion in beam sea which is 20% higher than experimental result. The reason may be that the viscous damping is nonlinear and linearized damping is under-predicted for large amplitude roll motion. Fig.13 shows the comparisons of time series in head sea and beam sea. The times series obtained by numerical simulation agree quite well with experimental re鄄 sults, which also demonstrates the reliability of numerical tool. 5.2.2 Comparisons between different barges The time domain simulations are also carried out for three different barges in the irregu鄄 lar wave. The wave condition is also given by a PM spectrum with significant wave height of 5.4 m and peak period of 13.5 sec, and the direction includes 180, 135, 90, 45 and 0deg. The maximum values of motion responses are shown in Fig.14. Barge-3 has the smallest heave mo鄄 tion in all 5 directions, and Barge-2 has the smallest roll motion in all 5 directions. For the pitch motion, the results of Barge-1 is nearly symmetrical for head sea and following sea, while the results of Barge-3 is not and the largest response occurs at 135deg wave heading. Tab.3 Comparison of statistic results between calculation and model test Min

180deg

135deg

90deg

Heave Pitch Heave Roll Pitch Heave Roll Pitch

Max

Mean

std.

CAL

EXP

CAL

EXP

CAL

EXP

CAL

EXP

-1.286 -2.700 -2.388 -7.814 -3.346 -5.152 -11.34 -0.650

-1.510 -2.527 -1.937 -7.255 -3.346 -4.877 -9.242 -1.627

1.240 2.728 2.130 7.724 3.573 5.380 11.650 0.627

1.556 2.576 1.945 7.487 3.325 5.043 9.665 1.363

0.010 -0.001 0.021 0.005 -0.001 0.011 -0.007 0.000

0.007 -0.019 -0.034 0.085 -0.014 0.008 0.001 -0.058

0.366 0.721 0.595 1.720 0.833 1.220 2.996 0.157

0.473 0.768 0.664 2.854 0.930 1.408 3.439 0.421

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(a) Heave in head sea

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(b) Pitch in head sea

(c) Heave in beam sea (d) Roll in beam sea Fig.13 Comparison of time series between calculation and model test

(a) Heave (b) Roll (c) Pitch Fig.14 Comparison of motion response maximum value among three barges

6 Concluding remarks Floatover is a new method for integrated topside installation of offshore platforms, and it has become more and more popular in recent years. The T-shaped barge concept is introduced in topside installation to both alleviate the constraints from jacket slot size and satisfy the larger lifting capacity and better transverse stability requirement. In this paper, hydrodynamic performance of T-shaped barge is investigated in frequency and time domain. The frequency domain analysis was executed with 3D potential flow code WAMIT, and motion RAOs and other hydrodynamic parameters are obtained. The time domain analysis was performed using FORTRAN code. Furthermore, corresponding model tests are also carried out in the State Key Laboratory of Ocean Engineering (SKLOE) basin. Through comparison，we can see that RAOs from experi鄄 ment agree quite well with numerical results, and that the effect of viscous roll damping is sig鄄 nificant for roll motion. The statistic results and times series in irregular wave test are also consistent with time domain simulation results obtained by self-compiled program. Finally, the comparisons of hydrodynamic performances among two T-shaped barges and one conventional barge are carried out. 1st and 2nd order wave forces of these three barges are calculated in frequency domain. The results show that T-shaped barge (Barge-3) has smaller roll moment response in majority sea conditions; T-shaped barge has larger pitch moment and

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longitudinal drift force in head sea than those in following sea for its asymmetry. The motion responses in irregular wave show that T-shaped barge has better performance in waves. Acknowledgement This work is supported by The Lloyd ’s Register Educational Trust (The LRET) through the joint centre involving University College London, Shanghai Jiao Tong University and Harbin Engineering University, to which the authors are most grateful. This work is also sup 鄄 ported by the Youth Innovation Fund of State Key Laboratory of Ocean Engineering (No. GKZD010059-21). References [1] O ’Neil L A, Fakas E. History, trends and evolution of float-over deck installation in open waters[C]// Proceedings of SPE2000 Conference on Society of Petroleum Engineers. Dallas, TX, USA, 2000. [2] Khaled S, Suresh P K, Eliseo C. Deck installation by floatover method in the Arabian Gulf[C]// Offshore Technology Conference, OTC11026. Houston, Texas, 1999. [3] Hartell W D, Beattie S M. Integrated, float-over deck design considerations[C]// Offshore Technology Conference, OTC8119. Houston, Texas, 1996. [4] Tribout C, Emery D, Weber P, Kaper R. Float -overs offshore west Africa [C]// Offshore Technology Conference, OTC 19073. Houston, Texas, 2007. [5] Seij M, Groot H. State of the art in float-overs[C]// Proceedings of 2007 Offshore Technology Conference. Houston, Texas, USA, 2007. [6] Wang A M, Jiang X Z, Yu C S, et al. Latest progress in floatover technologies for offshore installations and decommission鄄 ing[C]// Proceedings of the 20th International Offshore and Polar Engineering Conference, June 20-25, 2010. Beijing, China, 2010: 9-20. [7] Lee C H, Newman J N. Computation of wave effects using the panel method[M]. Numerical Models in Fluid-Structure Interaction, WIT Press, Southhampton, 2004. [8] Xu Xin, Yang Jianmin, Lu Haining. Experimental and numerical analysis for floatover installation on jacket[J]. Journal of Shanghai Jiaotong University, 2011, 45: 439-445. [9] Xu Xin, Li Xin, Lu Haining, Xiao Longfei, Yang Jianmin. An experimental and numerical study on motions of three adja 鄄 cent barges in floatover installation[C]// Proceedings of the 22nd International Offshore and Polar Engineering Conference, June, 2012. Rhodes, Greece, 2012. [10] Xu Xin, Yang Jianmin, Li Xin, Xiao Longfei. A study of floatover installation onto jacket with two barges[C]// 17th An 鄄 nual Offshore Symposium of SNAME Texas Section, 2012. Houston, USA, 2012. [11] Pinkster J A. Low frequency second order wave exciting forces on floating structures[M]. NSMB Publication, 1980(650). [12] Maruo H. The drift of a body floating on waves [J]. Journal of Ship Research, 1960, 4(3): 1-10. [13] Newman J N. The drift force and moment on ships in waves[J]. Journal of Ship Research, 1967, 11(1): 51-60. [14] Cummins. The impulse response function and ship motions[J]. Schiffstechnik, 1962: 101-109. [15] Xu Xin, Li Xin, Yang Jianmin, Lu Haining. An experimental and numerical study on seakeeping of T-shaped barge in topside transportation[C]// Proceedings of the 23rd International Offshore and Polar Engineering Conference, June, 2012. Alaska, USA, 2012. [16] William H P, Saul A T , Vetterling W T. Numerical recipes in Fortran 77: The art of scientific computing[M]. 1986: 704708. [17] DNV-RP-C205 (2005). Environmental conditions and environmental loads[R]. 2007.

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组块运输中的 T 型驳船水动力性能研究许

鑫，杨建民，李

欣，吕海宁

（上海交通大学海洋工程国家重点实验室，上海 200240 ）摘要 : 在浮托运输和安装中，为了满足平台桩腿间距对安装驳船宽度的限制以及驳船足够的横稳性需要，提出了 T 型驳船的概念。和传统的驳船相比，T 型驳船首尾宽度相差较大，因而具有一些较好的水动力性能。文中分别从频域和时域对

T型驳船和传统驳船的水动力性能进行了比较研究。在频域计算程序 WAMIT 的辅助下，得到了驳船的运动幅值响应算子（RAO）和波浪慢漂力，同时使用 FORTRAN 自编程序对驳船在不规则波浪下的运动进行时域模拟，得到运动时历和统计值。此外，开展了相应的模型试验研究来验证数值计算结果。通过比较模型试验和数值模拟的结果，发现两者十分吻合，从而验证了数值模拟的可靠性。在此基础上对不同船型的水动力计算结果进行了比较，结果表明 T 型驳船在组块运输过程中具有较好的水动力性能。关键词 : 浮托法； T 型驳船；海上运输；水动力性能中图分类号 : U661.32 作者简介：许

文献标识码 : A

鑫（1988- ），男，上海交通大学船舶海洋与建筑工程学院博士研究生，[email protected] ；

杨建民（1958- ），男，上海交通大学船舶海洋与建筑工程学院教授 / 博士生导师；李

欣（1975- ），女，上海交通大学船舶海洋与建筑工程学院副教授；

吕海宁（1979- ），男，上海交通大学船舶海洋与建筑工程学院讲师。

组块运输中的T型驳船水动力性能研究作者：作者单位：刊名：

许鑫，杨建民，李欣，吕海宁， XU Xin， YANG Jian-min， LI Xin， LU Hai-ning 上海交通大学海洋工程国家重点实验室,上海,200240

英文刊名：

Journal of Ship Mechanics

年，卷(期)：

2013(12)

船舶力学

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