The Experts below are selected from a list of 111 Experts worldwide ranked by ideXlab platform
M R Renilson - One of the best experts on this subject based on the ideXlab platform.
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A METHOD OF CALCULATING THE SHIP-BANK INTERACTION FORCES AND MOMENTS IN RESTRICTED WATER
International shipbuilding progress, 1993Co-Authors: L J Doctors, M R RenilsonAbstract:In order to investigate the influence of a bank on the manoeuvring of a ship in restricted water, a series of model tests were conducted. The ship-to-bank distance, water depth, bank slope, hullform, vessel speed and Propeller Rpm were varied. Empirical equations were developed using a regression analysis on the experimental data. These relationships are used to approximate the bank-induced sway force and yaw moment in the mathematical model used in shiphandling simulator at the Australian Maritime College.
L J Doctors - One of the best experts on this subject based on the ideXlab platform.
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A METHOD OF CALCULATING THE SHIP-BANK INTERACTION FORCES AND MOMENTS IN RESTRICTED WATER
International shipbuilding progress, 1993Co-Authors: L J Doctors, M R RenilsonAbstract:In order to investigate the influence of a bank on the manoeuvring of a ship in restricted water, a series of model tests were conducted. The ship-to-bank distance, water depth, bank slope, hullform, vessel speed and Propeller Rpm were varied. Empirical equations were developed using a regression analysis on the experimental data. These relationships are used to approximate the bank-induced sway force and yaw moment in the mathematical model used in shiphandling simulator at the Australian Maritime College.
Marc Vantorre - One of the best experts on this subject based on the ideXlab platform.
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Development of a test program for the prediction of ship manoeuvrability in deep and shallow water
2006Co-Authors: Katrien Eloot, Marc VantorreAbstract: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 contributions of the modules hull, Propeller and rudder in shallow water: as an example, stationary oblique towing and harmonic sway tests may lead to different results, while the reliability of the test results is much more sensitive to the selected test parameters during PMM tests. Due to the reduced under keel clearance even unusual phenomena may occur.
C.b. Barrass - One of the best experts on this subject based on the ideXlab platform.
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Reduced ship speed and decreased Propeller revolutions in shallow waters
Ship Design and Performance for Masters and Mates, 2004Co-Authors: C.b. BarrassAbstract:This chapter is designed to discuss reduced ship speed and decreased Propeller revolutions in shallow waters. If a ship is in open water conditions, there is an artificial boundary Port and Starboard, parallel to her centerline, beyond which there are no changes in ship speed, ship resistance, or in ship squat. This artificial boundary is known as a width of influence (F D ). When a ship operates in shallow water her speed and Propeller revolutions decrease. For the same input of engine power, her performance is not as good as when she is in deep water. The reasons for these decreases are: the ship produces more waves, which, in turn, produces more wave-making resistance thus causing extra drag to the vessel; dynamical forces, emanating from the bottom shell travel downwards to the river or the seabed and reflect back onto the underside of the vessel; due to increased turbulence at the aft end if the ship, the Propeller efficiency, the Propeller Rpm and the delivered power are all reduced.
Kohei Ohtsu - One of the best experts on this subject based on the ideXlab platform.
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Statistical Analysis and Control of Ship
IFAC Proceedings Volumes, 2009Co-Authors: Kohei OhtsuAbstract:Abstract The first parts of this paper describe the statistical time series analysis of ship's motions. The actual time series data are identified by the uni and multi-variate autoregressive models whose orders are determined by Akaike's Information Criterion(AIC). Various functions to analyse the ship's motions are defined in time and frequency domains and some salient features of ship's motions are derived from the time series data of the actual ship's motions. The latter half parts are contributed to the control problems of ship's heading to the given course and tracking ones along the given line and the regulation of main engine Propeller Rpm. All methods are corroborated by actual experiments on board.
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Statistical Identification and Optimal Control of Marine Engine System (Part 1)
Journal of the Society of Naval Architects of Japan, 1991Co-Authors: Masanori Ishizuka, Kohei Ohtsu, Toshiuki Hotta, Michio HorigomeAbstract:This paper deals with statistical identification problems of governor-Propeller Rpm control system in a marine diesel engine under operation at sea. The experiments were carried out after the ship's governor system was completely switched to a newly developed computer control system. P1 + random input signal was given to the main engine through the governor rack in the actuator. As the statistical model, a multi-variate auto regressive (MAR) model is adopted and the minimum AIC estimate method is used in order to fit the model to the actual data. A statistical bias free frequency response function, impulse response function of the governor-Propeller Rpm system are derived from the fitted AR model.
