Prediction of manoeuvring abilities of 10000 DWT pod-driven coastal tanker (original) (raw)
Related papers
Manoeuvring and Seakeeping Aspects of Pod-Driven Ships
Proceedings Of The Institution Of Mechanical Engineers, Part M: Journal Of Engineering For The Maritime Environment, 2005
An existing coupled non-linear six-degree-of-freedom model, which combines manoeuvring and seakeeping, is being enhanced for the simulation of motions of azimuthing pod-driven vessels. The equations of motions and modified numerical model for calculation of pod-induced propulsive and hull forces are presented. The modified numerical code has been verified using an extensive amount of experimental data for both conventional and poddriven roll-on roll-off passenger ship/ferry (ROPAX) hull forms. Comparisons have been made between conventional and podded control using zigzag and pull-out manoeuvring tests and significant motion amplitudes in waves, with the aim of investigating the directional stability and course-keeping ability of pod-driven ships, as well as the effect of large pod-induced heel angles to the turning and ship motions in waves. The results showed satisfactory agreement with experiments for the enhanced model. In the light of this investigation, the importance of hydrodynamic optimization for the azimuthing pod-driven ship design to eliminate any stability and control problems caused by design modifications has been demonstrated by the use of numerical simulations. Finally the efficiency of the azimuthing podded drives, in terms of overall controllability and seakeeping characteristics of ships, is discussed and conclusions are drawn.
A 6 DOF Manoeuvring Model for Controlled Ship Motions of POD-Driven Ships in Astern Seas
IFAC Proceedings Volumes, 2003
An existing mathematical model is being enhanced for pod-driven vessels. A numerical code which is based on a coupled non-linear 6-DOF model that can be used for identifying dangerous situations encountered by ships that travel in following and quartering seas, is being modified. A ROPAX vessel, for which extensive amount of data is available for both conventional and podded drives are used in order to validate the numerical model. Comparisons between conventional and podded models in different environmental conditions are presented. Copyright© 2003IFAC
Application of the IMO standard manoeuvres procedure for pod-driven ships
Journal of Marine Science and Technology, 2019
International Maritime Organisation (IMO) in the resolution MSC.137(76) Standards for Ship manoeuvrability presents the manoeuvring criteria that has to be satisfied by majority of seagoing ships. Together with the criteria, procedures for carrying out the manoeuvring tests are also presented. They however do not correspond directly to ships with non-conventional steering-propulsion devices, like pod drives. IMO is aware of this shortcoming and permits the use of comparative steering angles to the rudder angles specified by the resolution. To address this problem, a set of model tests has been carried out. Experiments with free-sailing manned model of a pod-driven gas carrier have been carried out to check the satisfaction of IMO criteria with systematically varying pod deflection angles. Results of the research show, that for tested pod-driven gas carrier, IMO manoeuvring criteria on turning circle are satisfied for much smaller deflection angles than recommended by IMO. Therefore a conclusion is made, that although the IMO manoeuvring criteria are valid for pod-driven ships and can be applied directly, the procedure for carrying out especially turning circle tests might be for pod-driven ships reconsidered.
Evaluation of Mathematical Models for Tankers' Maneuvering Motions
Journal of ETA Maritime Science, 2017
In this study, the maneuvering performance of two tanker ships, KVLCC1 and KVLCC2 which have different stern forms are predicted using a system-based method. Two different 3 DOF (degrees of freedom) mathematical models based on the MMG(Maneuvering Modeling Group) concept areappliedwith the difference in representing lateral force and yawing moment by second and third order polynomials respectively. Hydrodynamic coefficients and related parameters used in the mathematical models of the same scale models of KVLCC1 and KVLCC2 ships are estimated by using experimental data of NMRI (National Maritime Research Institute). The simulations of turning circle with rudder angle ±35 o , zigzag(±10 o /±10 o) and zigzag (±20 o /±20 o) maneuvers are carried out and compared with free running model test data of MARIN (Maritime Research Institute Netherlands) in this study. As a result of the analysis, it can be summarised that MMG model based on the third order polynomial is superior to the one based on the second order polynomial in view of estimation accuracy of lateral hull force and yawing moment.
“Esso Osaka” tanker manoeuvrability investigations in deep and shallow water, using PMM
International shipbuilding progress, 1987
Results of the experimental investigation of the effects of finite water depth on the hydrodynamic forces and moments acting on ship model moving in the horizontal plane are presented. The structure of the mathematical model used is verified after the multiple hnear regression and dispersion analysis methods. Comparison between the fuh scale and predicted ship manoeuvrabhity characteristics are made. This work is carried out at BSHC, Varna, Bulgaria with the help of PMM. 2.1. Experimental equipment and ship model
Equivalent standard manoeuvres for pod-driven ships
Ocean Engineering, 2019
Procedures for carrying out the manoeuvring tests presented in International Maritime Organisation (IMO) resolution MSC.137(76) are based on the capabilities of ships with conventional steering-propulsion systems. Therefore they do not correspond to ships with other steering-propulsion devices, like pod drives. IMO is aware of this shortcoming and for ships with non-conventional steering and propulsion system may permit the use of comparative steering angles to the rudder angles specified by the resolution. To elaborate these comparative angles for pod-driven gas carrier, experiments with free-sailing manned model have been carried out. For comparison two sister ships have been taken into consideration, i.e. twin-pod and twin-propeller twin-rudder configurations. For both ship versions, manoeuvres according to standard IMO procedures have been carried out. For twin-pod configuration, additionally manoeuvres with various pod propulsor settings have been performed to find the comparative, i.e. rudder-equivalent pod propulsor angles. Results show an obvious fact, that for twin-pod ship version similar results of standard manoeuvre parameters, as for twin-propeller twin-rudder version, are obtained for other than IMO recommended 35 � steering angle. It is shown that, for turning circle parameters, a single comparative or rudder-equivalent angle does not exist. Various turning circle parameters are obtained for different pod propulsor angles.
2006
The Flemish waterways authorities are permanently concerned about safety of navigation to the Flemish harbours in order to maintain their present position in the European shipping market. Special attention is paid to the effect of the constant growth of ship dimensions, especially in the container trade, on the safety of shipping traffic. Access to and manoeuvring in harbours are characterised by a great diversity of kinematical and control parameters. In 2004-2005 a captive model test program has been executed with a 4.3 m model of an 8000 TEU containership (scale 1:81) combining three distinguished drafts and three under keel clearances from deep to very shallow water. This test program covering all possible combinations of ship velocities and propeller telegraph positions has been used to evaluate hull, propeller and rudder forces to be incorporated in a manoeuvring simulation model applicable in the four quadrants of operation. The influence of combinations of draft and under ke...
Manoeuvring forces on azimuthing podded propulsor model
Polish Maritime Research, 2007
Manoeuvring forces on azimuthing podded propulsor model This paper presents the preliminary part of comprehensive manoeuvring open-water tests of a gas carrier model. The paper focuses on open water experiments with an azimuthing podded propulsor. The test program was carried out in the cavitation tunnel and the large towing tank of Ship Hydromechanics Division, Ship Design and Research Centre, Gdańsk. The pod was tested as a pushing unit with a 161.3 mm diameter propeller. Steering forces were measured in the range of advance coefficient from 0.0 to 0.8 combined with the range of deflection angles from -45° up to +45°. Measurements on the pod without propeller were also performed. The experiment results are presented in the form of non-dimensional coefficients in function of advance coefficient and deflection angle. Analysis of the experimental results and the conclusions are presented.
2003
Most formulations of mathematical modelling of ship manoeuvres in shallow water discussed in literature are based on expressions for the deep water case. Several usual and unusual phenomena occurring during manoeuvres at limited under keel clearance (10% to 50%) are not considered. A tabular model for the hull forces is proposed, taking the shallow water condition as starting point, with the intention to cover wide ranges of kinematical parameters so that a great variety of manoeuvres can be simulated. The implementation of the mathematical model is based on captive model tests with 4 m models of the tanker Esso Osaka and a fourth generation container carrier. The experimental program consists of well-known, classical PMM test types combined with alternative tests. Preliminary guidelines are formulated for the selection of test parameters, taking account of their influence on the hydrodynamic coefficients.
Development of a test program for the prediction of ship manoeuvrability in deep and shallow water
2006
As in many coastal and estuary areas, navigation to and in the Belgian harbours takes place in environmental and operational conditions which differ from the design conditions of seagoing ships: water depth to draft ratios vary between 2.0 and 1.1 which means that the under keel clearance is often restricted to 10% of the ship’s draft. In addition, low ship velocities have to be considered as manoeuvring in harbour areas is characterised by a wide range of speed – propeller rpm combinations. Based on the results of captive model tests executed in the Towing Tank for Manoeuvres in Shallow Water (co-operation Flanders Hydraulics Research – Ghent University, Antwerp, Belgium) with a 6000 TEU containership and the tanker Esso Osaka, an optimized test program has been developed for the determination of a mathematical manoeuvring model in laterally unrestricted water. Contrary to deep water and service speed the selected test types and test parameters will influence the measured contribut...