Model Tests Research on A Float-Over Barge in Shallow Water Under the Undocking Conditions

2021 ◽  
Vol 35 (6) ◽  
pp. 933-942
Author(s):  
Li-cheng Qin ◽  
Hong-yan Ding ◽  
Pu-yang Zhang ◽  
Huai-liang Li ◽  
Wen-tai Yu
Keyword(s):  
Shallow Water ◽  
Model Tests

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.

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.

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 Validation of a New Shallow Water CALM Buoy Design

2013 ◽  
Author(s):  
A. Neil Williams ◽  
Williams G. McDougal
Keyword(s):  
Shallow Water ◽  
Experimental Validation ◽  
Numerical Models ◽  
Water Environment ◽  
Model Testing ◽  
Model Tests ◽  
Hydrodynamic Efficiency ◽  
Shallow Water Environment

This paper presents an overview of the model testing of a new turret-type CALM buoy concept developed by WISON for shallow water (20m–80m) applications. In the WISON design the outer body of the buoy is hexagonal, a geometry that allows for ease of fabrication while retaining hydrodynamic efficiency. The overall objective of the model tests was to demonstrate the performance of this new design for a typical shallow water environment under both operating and survival conditions. Additionally, the model tests were intended to provide data to calibrate the numerical models for buoy motions and line tensions used in the design, and to give guidance regarding the suitability of the buoy freeboard and deckhouse arrangement.

scholarly journals Model Tests for Shallow-Water Ship Maneuverability in Three Gorges Reservoir

2015 ◽  
Vol 22 (s1) ◽  
pp. 136-140
Author(s):  
Chuang Cai ◽  
Xinyong Cai ◽  
Yi Li
Keyword(s):  
Shallow Water ◽  
Scale Effect ◽  
Three Gorges Reservoir ◽  
Correction Method ◽  
Model Tests ◽  
Influential Factors ◽  
Three Gorges ◽  
Test Results ◽  
Experimental Basis ◽  
Ship Maneuverability

Abstract This paper conducts calibration tests on the shallow-water maneuverability of 1:100 ship models for the typical navigation fleets in Three Gorges Reservoir. Major influential factors for the maneuverability similitude between models and prototypes and for scale effect were identified. A correction method for model scale was also established through model tests. Test results indicate that, by correcting the model scales of various fleets based on scale effect, the maneuverability indexes K’ (dimensionless of K) and T’ (dimensionless of T) of ship models are suitable for shallow-water tests, and properly reflect the maneuvering characteristics of prototypes. The findings provide an experimental basis for the navigation safety in Three Gorges Reservoir.

Modeling the Maneuvering Behavior of Container Carriers in Shallow Water

2007 ◽  
Vol 51 (04) ◽  
pp. 287-296 ◽  
Author(s):  
G. Delefortrie ◽  
M. Vantorre
Keyword(s):  
Mathematical Model ◽  
Shallow Water ◽  
Independent Set ◽  
Model Tests ◽  
Forward Speed ◽  
Ship Maneuvering ◽  
Model Based ◽  
Captive Model Tests ◽  
Water Effects ◽  
The Mathematical Model

Due to the expansion of the dimensions of container vessels, the available maneuvering space in harbor areas and their access channels is decreasing as waterway authorities are often unable to increase the channel dimensions at the same pace. The under keel clearance is an especially important parameter for ship maneuver-ability and controllability. After an overview of the shallow water effects on ship maneuvering, a new mathematical maneuvering model based on captive model tests is introduced. The mathematical model is valid in a large under keel clearance range and is applicable in four quadrants of forward speed: propeller rate combinations, drift angles, and yaw angles. The mathematical model has been validated by means of an independent set of captive model tests.

Model Tests and Numerical Prediction of the Low Frequency Motions of a Moored Ship in Shallow Water With a Wave Splitting Method

2020 ◽  
Author(s):  
Nuno Fonseca ◽  
Galin Tahchiev ◽  
Sébastien Fouques ◽  
Carl Trygve Stansberg ◽  
José Miguel Rodrigues
Keyword(s):  
Shallow Water ◽  
Test Data ◽  
Numerical Models ◽  
Splitting Method ◽  
Low Frequency ◽  
Ocean Basin ◽  
Model Tests ◽  
Harmonic Waves ◽  
Frequency Wave ◽  
Numerical Predictions

Abstract Prediction of shallow water low frequency (LF) motions of vessels in the context of mooring analysis is challenging. Model tests are often performed to calibrate and validate numerical models and, in this way, reduce the uncertainty. Model tests are part of the positioning system qualifying process. However, model tests also present challenges and uncertainties related to parasitic low frequency wave systems which are unavoidable in shallow water ocean basin conditions. The paper presents model tests with a ship moored in shallow water (20 m), the analysis and discussion of the test data and comparisons with numerical predictions. The focus is on the low frequency motions and related wave drift forces. The tests have been performed in harmonic waves, bi-harmonic waves and irregular seastates, including conditions with and without current. The first part of the study consists of analysing the wave field measured by a long array of wave sensors distributed along the ocean basin. The analysis provides split wave systems, namely the low frequency components including the bound wave, the incoming free parasitic wave, the reflected component and additional very long waves. The second part proposes a method to calibrate and validate mooring analysis numerical models, based on comparisons with model test data which includes the unavoidable effects from parasitic waves. Simulations of LF motions with the calibrated model show a good agreement with the measurements.

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.

Experimental Study of Hydrodynamic Responses of a Single Floating Storage Tank With Internal Fluid

2017 ◽  
Author(s):  
Zhang Chi ◽  
Allan R. Magee ◽  
Wan Ling ◽  
Chien Ming Wang ◽  
Øyvind Hellan
Keyword(s):  
Shallow Water ◽  
Model Tests ◽  
Constant Current ◽  
Single Model ◽  
Floating Structure ◽  
Drag Forces ◽  
Oil Storage ◽  
Internal Fluid ◽  
Wave Basin ◽  
Six Dof

When floating structure with internal fluid compartment is close to other structures, the multibody interaction problem needs to be addressed in addition to the internal fluid influence. Furthermore, shallow water effects become important, especially when the gap between the floating structure and the sea floor is small. These issues are encountered when designing a novel floating oil storage facilities in nearshore area. To investigate these issues, floating models under 1:50 scale are built to perform model tests. The test set-up uses a set of flexible constraints working as fenders placed on frames to restrain the motions of the models in the horizontal plane. Various tests in waves are carried out to measure motion responses of single model in waves with different filling levels and stiffness of “fenders”. The reaction forces on the “fenders” are also measured. Several regular wave conditions are selected to perform tests on double model system to investigate multibody interactions under the influence of internal fluid and effects of waves between the tanks. The drag forces for both single model and double models are measured by performing model tests under constant current from different directions, to check the shielding effects. The tests are performed in shallow-water wave basin, and the constant currents tests are performed by towing the models in a flume tank. Both facilities are located at National University of Singapore (NUS). This paper presents the detailed setting of the model tests. The single model’s RAOs with 20% filling level of internal fluid are given to demonstrate the influence of internal fluid on the motions. The performances of a single tank, including six DOF motions are shown. The results will be used for validation of numerical analysis results in the near future.

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