Resonant Water Motion Between a Ship and a Terminal in Shallow Water

2007 ◽  
Author(s):  
Trygve Kristiansen ◽  
Odd M. Faltinsen
Keyword(s):  
Shallow Water ◽  
Time Domain ◽  
Vertical Wall ◽  
Model Tests ◽  
Ship Model ◽  
Wave Flume ◽  
Wave Elevation ◽  
Water Conditions ◽  
Sharp Corners ◽  
Hydrodynamical Problem

This work focus on the hydrodynamical problem of an LNG carrier near a GBS-type offshore terminal subject to incoming waves in medium deep to shallow water conditions. The work is restricted to 2D and the ship is restrained from moving. The resonant behaviour of the fluid in the gap between the ship and the terminal is investigated. The problem is investigated by means of a numerical model and model tests. Potential theory is assumed and a linear as well as a nonlinear time-domain numerical wavetank based on a boundary element method with a Mixed Eularian-Lagrangian approach is implemented for this purpose. Model tests (near 2D) of a mid-ship section near a vertical wall is carried out in a 26.5m long and 0.595m wide wave flume in model scale 1:70. In full scale the ship beam is 45m and the ship draft 12m. The ship model is constructed in such a way as to avoid flow separation, i.e. no sharp corners. Several parameters are varied: Water depth, wave period and wave steepness. Wave elevation is measured at twelve locations.

Studies on Resonant Water Motion Between a Ship and a Fixed Terminal in Shallow Water

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Trygve Kristiansen ◽  
Odd M. Faltinsen
Keyword(s):  
Shallow Water ◽  
Vertical Wall ◽  
Model Tests ◽  
Ship Model ◽  
Wave Flume ◽  
Wave Elevation ◽  
Resonant Behavior ◽  
Liquid Natural Gas ◽  
Sharp Corners ◽  
Hydrodynamical Problem

This work focuses on the hydrodynamical problem of a Liquid Natural Gas (LNG) carrier near a Gravity Based Structure (GBS) -type offshore terminal subject to incoming waves in medium deep to shallow water conditions. The work is restricted to 2D, and the ship is restrained from moving. The resonant behavior of the fluid in the gap between the ship and the terminal is investigated. The problem is investigated by means of a numerical model and model tests. Potential theory is assumed, and a linear as well as a nonlinear time-domain numerical wavetank based on a boundary element method with a mixed Eulerian–Lagrangian approach is implemented for this purpose. Model tests (near 2D) of a midship section near a vertical wall are carried out in a 26.5m long and 0.595m wide wave flume in model scale 1:70. In full scale the ship beam is 45m and the ship draft is 12m. The ship model is constructed in such a way as to avoid flow separation, i.e., no sharp corners. Several parameters are varied: water depth, wave period, and wave steepness. Wave elevation is measured at 12 locations.

Experimental Study of a Tanker Ship Squat in Shallow Water

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Mohammadreza Fathi Kazerooni ◽  
Mohammad Saeed Seif
Keyword(s):  
Experimental Study ◽  
Shallow Water ◽  
Experimental Approach ◽  
Model Tests ◽  
Ship Hull ◽  
Experimental Results ◽  
Shallow Waters ◽  
Towing Tank ◽  
Ship Model

One of the phenomena restricting the tanker navigation in shallow waters is reduction of under keel clearance in the terms of sinkage and dynamic trim that is called squatting. According to the complexity of flow around ship hull, one of the best methods to predict the ship squat is experimental approach based on model tests in the towing tank. In this study model tests for tanker ship model had been held in the towing tank and squat of the model are measured and analyzed. Based on experimental results suitable formulae for prediction of these types of ship squat in fairways are obtained.

Research on Wash Wave in Shallow Water Caused by Ship Moving at High Speed

2012 ◽  
Vol 212-213 ◽  
pp. 104-107
Author(s):  
Hui Deng ◽  
Zhi Hong Zhang ◽  
Tao Miao ◽  
Jian Nong Gu
Keyword(s):  
Numerical Simulation ◽  
Shallow Water ◽  
Water Wave ◽  
High Speed ◽  
Pressure Variation ◽  
Measuring System ◽  
Ship Model ◽  
Wave Elevation ◽  
Supercritical Speed ◽  
Good Agreement

Based on the theory of shallow-water wave, the theoretical model was established for calculating wash wave caused by ship moving at subcritical and supercritical speed. Wave elevation and pressure variation were obtained by numerical simulation, and their features were analyzed. A measuring system of wash wave and pressure variation was developed, and wave elevation and pressure variation induced by a towed ship model were measured. A good agreement existed between the calculated with experimental results.

Innovative Ice Protection for Shallow Water Drilling: Part II — SIB Model Testing in Ice

2008 ◽  
Author(s):  
Arne Gu¨rtner ◽  
Ove Tobias Gudmestad
Keyword(s):  
Shallow Water ◽  
Conceptual Design ◽  
Caspian Sea ◽  
Companion Paper ◽  
Model Testing ◽  
Model Tests ◽  
Full Scale ◽  
Ship Model ◽  
Water Developments ◽  
Broken Ice

Model tests on the Shoulder Ice Barrier (SIB) were performed in the large ice tank of the Hamburg Ship Model Basin (HSVA) during July 2007. The concept of the SIB has previously been presented in a companion paper under the same title at the OMAE 2006 (Gu¨rtner et al., 2006). Model tests were performed to investigate the conceptual design and force conditions under ice impact. Design conditions for the Northern Caspian Sea were assumed for the model tests. The characteristic shoulder sections’ inclination has been varied to investigate their contribution towards stabilizing broken ice and to prevent ice from over-riding. Ice up-riding onto the barrier contributes towards increased vertical forces. The global vertical forces showed to be higher than the global horizontal forces, and in particular when ice grounding was observed. Even under extreme rubble heights of up to 9.4 m (full scale), ice overtopping the structure was effectively prevented. The SIB showed the potential to be utilized as ice protection structure for future shallow water developments.

Numerical Estimation of Relative Wave Elevation on a Semi-Submersible Vessel

2021 ◽  
Author(s):  
Christian Lena ◽  
Rinnert van Basten Batenburg
Keyword(s):  
The Netherlands ◽  
Time Domain ◽  
Potential Flow ◽  
Model Tests ◽  
Regular Wave ◽  
Numerical Estimation ◽  
Wave Elevation ◽  
Landing Platform ◽  
Heavy Lift ◽  
Wave Elevations

Abstract Ambition of this research was to numerically reproduce the relative wave elevations measured on and around a semi-submersible vessel during model tests performed at MARIN (Maritime Research Institute of the Netherlands). Model tests were performed on a semi-submersible model representing, in different setup configurations, a heavy lift vessel and a LPD (Landing Platform Dock). Relative wave elevations were measured at 47 locations on and around the vessel. Tests were made with different regular wave conditions and headings, at anchor, with the model fixed in a soft mooring setup. Data from model tests were used to calibrate and run a time domain potential flow boundary element tool with particular focus on the relative wave elevation at the 47 locations. A comparison between numerical and experimental results is proposed in this paper.

A Quasi-three-dimensional Finite-volume Shallow Water Model for Green Water on Deck

2013 ◽  
Vol 57 (03) ◽  
pp. 125-140
Author(s):  
Daniel A. Liut ◽  
Kenneth M. Weems ◽  
Tin-Guen Yen
Keyword(s):  
Shallow Water ◽  
Finite Volume ◽  
Time Domain ◽  
Degrees Of Freedom ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Green Water ◽  
Water Model ◽  
Ship Motions ◽  
Shallow Water Model

A quasi-three-dimensional hydrodynamic model is presented to simulate shallow water phenomena. The method is based on a finite-volume approach designed to solve shallow water equations in the time domain. The nonlinearities of the governing equations are considered. The methodology can be used to compute green water effects on a variety of platforms with six-degrees-of-freedom motions. Different boundary and initial conditions can be applied for multiple types of moving platforms, like a ship's deck, tanks, etc. Comparisons with experimental data are discussed. The shallow water model has been integrated with the Large Amplitude Motions Program to compute the effects of green water flow over decks within a time-domain simulation of ship motions in waves. Results associated to this implementation are presented.

Determination of the added masses and damping coefficients during coupled motions of two ships in shallow water parallel to the vertical wall

2021 ◽  
pp. 16-25
Author(s):  
В.Ю. Семенова ◽  
К.И. Баканов
Keyword(s):  
Shallow Water ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Hydrodynamic Coefficients ◽  
Damping Coefficients ◽  
Added Masses ◽  
Joint Motions ◽  
National Practice ◽  
Simultaneous Influence

В статье рассматривается определение коэффициентов демпфирования и присоединенных масс, возникающих при совместной качке двух судов в условиях мелководья параллельно вертикальной стенке на основании решения трехмерной потенциальной задачи. Определение гидродинамических коэффициентов осуществляется на основании методов интегральных уравнений и зеркальных отображений. Представленное решение в отечественной практике является новым. В статье приводятся результаты расчетов коэффициентов присоединенных масс и демпфирования, возникающих при качке двух одинаковых судов, расположенных лагом к волнению и параллельно вертикальной стенке в зависимости от изменения расстояний как между судами, так и между судами и вертикальной стенкой. Проводится исследование влияния различных фарватеров на величины гидродинамических коэффициентов, а именно: мелководного фарватера, мелководного фарватера с вертикальной стенкой, мелководного фарватера со вторым параллельно качающимся судном и мелководного фарватера с вертикальной стенкой и вторым судном. Таким образом, в работе учитывается одновременное влияния мелководья, вертикальной стенки и второго судна. Показано увеличение значений коэффициентов присоединенных масс и демпфирования при уменьшении расстояний между судами и между судами и вертикальной стенкой. Также показано значительное совместное влияние вертикальной стенки и второго судна на коэффициенты присоединенных масс и демпфирования по сравнению с другими видами стесненных фарватеров. The article discusses the determination of damping coefficients and added masses arising from the joint motions of two ships in shallow water conditions parallel to the vertical wall based on the solution of a three-dimensional potential problem. Determination of hydrodynamic coefficients is carried out on the basis of the methods of integral equations and mirror images. The solution presented in the national practice is new The article presents the results of calculating the coefficients of added masses and damping arising from the motions of two identical ships located lagged to the sea and parallel to the vertical wall, depending on the change in the distances between the ships and between the ships and the vertical wall. A study is being made of the influence of various waterways on the values ​​of hydrodynamic coefficients, namely: a shallow waterway, a shallow waterway with a vertical wall, a shallow waterway with a second parallel oscillating ship and a shallow waterway with a vertical wall and a second ship. Thus, the work takes into account the simultaneous influence of shallow water, vertical wall and the second ship. An increase in the values of the coefficients of added masses and damping with a decrease in the distances between ships and between ships and the vertical wall is shown. It also shows a significant combined effect of the vertical wall and the second ship on the added mass and damping coefficients in comparison with other types of constrained waterways.

Resistance Tests of an Articulated Pusher Barge System in Deep and Shallow Water

2021 ◽  
Author(s):  
Li Zhang ◽  
Lei Xing ◽  
Mingyu Dong ◽  
Weimin Chen
Keyword(s):  
Shallow Water ◽  
Water Depth ◽  
Deep Water ◽  
Water Resistance ◽  
Model Tests ◽  
System 2 ◽  
Changing Trend ◽  
The Difference ◽  
Transport Vessel ◽  
Resistance Performance

Abstract Articulated pusher barge vessel is a short-distance transport vessel with good economic performance and practicability, which is widely used in the Yangtze River of China. In this present work, the resistance performance of articulated pusher barge vessel in deep water and shallow water was studied by model tests in the towing tank and basin of Shanghai Ship and Shipping Research Institute. During the experimental investigation, the articulated pusher barge vessel was divided into three parts: the pusher, the barge and the articulated pusher barge system. Firstly, the deep water resistance performance of the articulated pusher barge system, barge and the pusher at design draught T was studied, then the water depth h was adjusted, and the shallow water resistance at h/T = 2.0, 1.5 and 1.2 was tested and studied respectively, and the difference between deep water resistance and shallow water resistance at design draught were compared. The results of model tests and analysis show that: 1) in the study of deep water resistance, the total resistance of the barge was larger than that of the articulated pusher barge system. 2) for the barge, the shallow water resistance increases about 0.4–0.7 times at h/T = 2.0, 0.5–1.1 times at h/T = 1.5, and 0.7–2.3 times at h/T = 1.2. 3) for the pusher, the shallow water resistance increases about 1.0–0.4 times at h/T = 2.7, 1.2–0.9 times at h/T = 2.0, and 1.7–2.4 times at h/T = 1.6. 4) for the articulated pusher barge system, the shallow water resistance increases about 0.2–0.3 times at h/T = 2.0, 0.5–1.3 times at h/T = 1.5, and 1.0–3.5 times at h/T = 1.2. Furthermore, the water depth Froude number Frh in shallow water was compared with the changing trend of resistance in shallow water.

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