Experimental investigation of single blade loads by captive model tests in pure oblique flow. Part II: Propeller in-plane loads and preliminary comparison of single blade loads during transient phases

The paper provides the results of model tests planned with an optimized experimental design method. Captive-model tests have been carried out according to such a design on a computerized planar-motion carriage with a model of a fast catamaran with five varying factors (drift angle, rate-of-yaw amplitude, sinkage, trim and heel angles) and with all six force/moment components measured at each run. The measured values were used after preprocessing for construction of polynomial regression models for all force components acting upon the catamaran's hulls. It is demonstrated that the optimized experimental design method allows rather complicated mathematical models for maneuvering hydrodynamics forces to be obtained from captive model tests at a reasonable level of effort.

Download Full-text

Experimental Investigation of the Shipping of Water on the Bow of a Containership

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.2087527 ◽

2005 ◽

Vol 127 (4) ◽

pp. 322-330 ◽

Cited By ~ 11

Author(s):

Nuno Fonseca ◽

C. Guedes Soares

Keyword(s):

Experimental Investigation ◽

Large Amplitude ◽

Model Tests ◽

Impact Pressure ◽

Irregular Waves ◽

Total Force ◽

First Line ◽

The Absolute ◽

The Impact ◽

Relative Motions

The paper presents the results of an experimental investigation of the shipping of water on the bow of a containership. Model tests were carried out in head regular and irregular waves of large amplitude, and measurements were taken of: the absolute and relative motions, the structural loads, the height of water and the impact pressure on the deck, and the horizontal impact pressure and total force on the first line of containers on the bow.

Download Full-text

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.

Download Full-text

Experimental Investigation of the Shipping of Water on the Bow of a Containership

Volume 3: Materials Technology; Ocean Engineering; Polar and Arctic Sciences and Technology; Workshops ◽

10.1115/omae2003-37456 ◽

2003 ◽

Cited By ~ 2

Author(s):

Nuno Fonseca ◽

Carlos Guedes Soares

Keyword(s):

Experimental Investigation ◽

Large Amplitude ◽

Model Tests ◽

Impact Pressure ◽

Irregular Waves ◽

Total Force ◽

First Line ◽

The Absolute ◽

The Impact ◽

Relative Motions

The paper presents the results of an experimental investigation of the shipping of water on the bow of a containership. Model tests were carried out in head regular and irregular waves of large amplitude, and measurements were taken of: the absolute and relative motions, the structural loads, the height of water and the impact pressure on the deck, and the horizontal impact pressure and total force on the first line of containers on the bow.

Download Full-text

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.

Download Full-text