Captive Model Tests for Assessing Maneuverability of a Damaged Surface Combatant with Initial Heel Angle

The present study is about the application of a four-degree-of-freedom (4DOF) maneuvering mathematical model based on Abkowitz’s model for assessing damaged ship maneuverability with initial asymmetry. A scaled model of the Office of Naval Research Tumblehome hull with a damaged compartment was used as the test model. Based on the survivability regulations for naval vessels, the damaged compartment was designed and located near the bow, such that it had an initial heel and trim. Static and dynamic captive model tests were performed on the damaged ship model to determine the maneuvering coefficients for the maneuvering mathematical model. Maneuvering simulations were carried out with the captive model test data and 4DOF maneuvering mathematical model. The advance speed in the maneuver reduced more in the damaged condition than in the intact condition, and maneuverability was severely degraded during starboard turning.

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Modeling the Maneuvering Behavior of Container Carriers in Shallow Water

Journal of Ship Research ◽

10.5957/jsr.2007.51.4.287 ◽

2007 ◽

Vol 51 (04) ◽

pp. 287-296 ◽

Cited By ~ 4

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.

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Model Tests for Safe-Return-to-Port of a Damaged Ship in Waves

10.5957/wmtc-2015-229 ◽

2015 ◽

Author(s):

Jeonghwa Seo ◽

Cristobal Santiago Bravo ◽

Shin Hyung Rhee

Keyword(s):

Degrees Of Freedom ◽

Feedback System ◽

Model Tests ◽

Measurement Unit ◽

Test Model ◽

Motion Response ◽

Six Degrees Of Freedom ◽

Heading Angle ◽

Wave Conditions ◽

Damaged Ship

A series of tests using a course-keeping model ship with an autopilot system were carried out in a towing tank for research on Safe-Return-to-Port (SRTP). The autopilot system controls the rudder angle and propeller revolution rate by a feedback system. The variation of the heading angle of the test model with different control parameters was investigated first, to ensure that the test model had sufficient course-keeping maneuverability in severe wave conditions. The wave conditions and propeller revolution rate were selected based on SRTP regulations. Tests were conducted in wave conditions corresponding to sea states 4 to 6. The six-degrees-of-freedom motion response of the test model was measured by a wireless inertial measurement unit and gyro sensors to achieve fully wireless model tests. The advance speed and motion response in various wave conditions were measured and analyzed to investigate the effects of flooding behavior in a damaged condition and of waves on the propulsion and maneuvering performance of the damaged ship model.

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Numerical Estimation of Hull Hydrodynamic Derivatives in Ship Maneuvering Prediction

Polish Maritime Research ◽

10.2478/pomr-2021-0020 ◽

2021 ◽

Vol 28 (2) ◽

pp. 46-53

Author(s):

Radosław Kołodziej ◽

Paweł Hoffmann

Keyword(s):

Model Tests ◽

Circular Motion ◽

Computational Method ◽

Design Stage ◽

Hydrodynamic Characteristics ◽

Ship Maneuvering ◽

Hydrodynamic Derivatives ◽

Captive Model Tests ◽

Ship Maneuverability ◽

Free Running

Abstract Prediction of the maneuvering characteristics of a ship at the design stage can be done by means of model tests, computational simulations or a combination of both. The model tests can be realized as a direct simulation of the standard maneuvers with the free running model, which gives the most accurate results but is also the least affordable, as it requires a very large tank or natural lake, as well as the complex equipment of the model. Alternatively, a captive model test can be used to identify the hydrodynamic characteristics of the hull, which can be used to simulate the standard maneuvers with the use of dedicated software. Two types of captive model tests are distinguished: circular motion tests (CMT) and planar motion mechanism tests (PMM). The paper presents an attempt to develop a computational method for ship maneuverability prediction in which the hydrodynamic characteristics of the hull are identified by means of computational fluid dynamics (CFD). The CFD analyses presented here directly simulate the circular motion test. The resulting hull characteristics are verified against the available literature data, and the results of the simulations are verified against the results of free running model tests. Reasonable agreement shows the large potential of the proposed method.

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Experiments and CFD Analysis on Safe-Return-to-Port of a Damaged Ship in Head and Following Seas

Volume 1B, Symposia: Fluid Mechanics (Fundamental Issues and Perspectives; Industrial and Environmental Applications); Multiphase Flow and Systems (Multiscale Methods; Noninvasive Measurements; Numerical Methods; Heat Transfer; Performance); Transport Phenomena (Clean Energy; Mixing; Manufacturing and Materials Processing); Turbulent Flows — Issues and Perspectives; Algorithms and Applications for High Performance CFD Computation; Fluid Power; Fluid Dynamics of Wind Energy; Marine Hydrodynamics ◽

10.1115/fedsm2016-7727 ◽

2016 ◽

Cited By ~ 1

Author(s):

Jeonghwa Seo ◽

Shin Hyung Rhee

Keyword(s):

Degrees Of Freedom ◽

Model Tests ◽

Measurement Unit ◽

Test Model ◽

Cfd Analysis ◽

Following Seas ◽

Passenger Ships ◽

Seakeeping Performance ◽

Thrust And Torque ◽

Damaged Ship

In the present study, model tests in a towing tank and computational fluid dynamics (CFD) analysis on damaged stability of a passenger ship in waves were conducted. An autopilot system that controlled the rudder angle was introduced to the test model, for course-keeping maneuverability of the test model in asymmetric damaged condition. Following the regulations of the safe-return-to-port (SRTP) of passenger ships, the ship speed in the test corresponded to 8 knots in the full scale. In the damaged condition, a compartment at midship was flooded and the stability of the model degraded. Tests were conducted in head and following seas. Wave conditions correspond to Sea states 4 to 6. The six-degrees-of-freedom (6DOF) motion response of the test model was measured by a wireless inertial measurement unit and gyro sensors to achieve fully untethered model tests. Thrust and torque on the propulsive system and free-surface height in the damaged compartment were also measured. CFD analysis was performed in the same condition as the experiments. 6DOF motion, the propulsion, and flooding behavior were analyzed. CFD analysis results were compared with the experimental results. In addition, some physical features that could not be measured by experiments were identified and investigated. With the results of the experiments and CFD analysis, the effects of incoming waves and flooding behavior on the propulsion and seakeeping performance of the damaged ship model could be identified.

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Numerical Calculation of Added Mass for Ship Dynamic Stability by High Order Panel Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.97-98.802 ◽

2011 ◽

Vol 97-98 ◽

pp. 802-805

Author(s):

Hua Ming Wang ◽

Han Xing Zhao ◽

Yu Long Yang ◽

Xiao Song Rui

Keyword(s):

Dynamic Stability ◽

Three Dimensional ◽

Added Mass ◽

Model Tests ◽

Panel Method ◽

Design Stage ◽

Captive Model Tests ◽

Ship Maneuverability ◽

Wigley Hull ◽

Free Running

IMO Standards for ship maneuverability require prediction of ship’s maneuvering performance at the design stage. For this purpose, various methods such as those based on free running model tests, captive model tests or numerical simulation using mathematical models can be used. While this paper describes a numerical method for estimating ship’s dynamic stability by computing the linear sway and yaw added mass coefficients using a higher-order panel method based on Non-Uniform Rational B-Spline. Three dimensional forward-speed radiation problems are formulated and solved in frequency domain. The linear hydrodynamic coefficients are calculated and preliminary results are presented for a modified Wigley hull.

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