1,721,036 research outputs found
CODLAW Ship Propulsion Simulation: Performance Optimization by Smart Control
No full textThe paper presents an integrated simulation study aimed at ship’s performance prediction, during both
sailing and motor propulsion, for a Combined Diesel eLectric and Wind (CODLAW) propulsion plant
installed on board of the illustrious tall ship “Amerigo Vespucci”. The ship, recently interested by a
complete platform system revamping, will be equipped with the most innovative IFEP plant
(Integrated Full Electric Propulsion), still preserving the rigs to honour the seafaring tradition. The
study is focused on the behaviour of the new electric propulsion motor, driving the fixed pitch
propeller, during sailing navigation condition, and in particular on the negative effect of the trailing
propeller. A newly developed control system will drive the propeller to the “zero thrust” mode during
sailing, for several wind conditions, in order to optimize the ship performance. Feasibility and benefits
of this propulsion option are investigated through a motor – sailing propulsion simulator, developed in
the MatLab-Simulink environment, and off-line CFD analysis carried out for the evaluation of the soft
sails aerodynamics
A mathematical model of the propeller pitch change mechanism for the marine propulsion control design
No full textThe paper is mainly focused on the mathematical model of the control pitch mechanism for a marine controllable pitch propeller (CPP), able to perform the propeller blade position change and to give a proper information about the oil pressures, produced inside the CPP hub. In fact, too high pressures can be responsible for the mechanism failure, then they should be always under examination by the ship automation. With regard to the traditional representation of the few spindle torque data reported in literature, in the proposed mathematical model the transportation inertial forces and the Coriolis inertial forces acting on the propeller blade are evaluated taking into account the yaw motion of the ship, the propeller speed (including shaft accelerations and decelerations) and the blade turning during the pitch change. On the basis of the introduced procedure, it is developed the CPP model which is part of an overall propulsion simulator, representing the dynamic behaviour of a twin-screw fast vessel. The aim of the work is to represent the ship propulsion dynamics by time domain simulation, on the ground of which the automation designers can develop and test several propulsion control options. A brief description of the simulation approach adopted for the vessel crash stop is illustrated at the end of this paper. In particular, the propulsion control action is studied taking into account machinery performance and constraints, including also the control pitch mechanism feedback in terms of allowable forces and pressures
Advances in automation design for fast vessels propulsion
No full textABSTRACT: Superior performance, flexibility and energy efficiency, make more and more important the automation role in marine propulsion applications. Controller hardware and software should be designed for safe operation in all conditions, as well as for high dynamic performance. The increasing complexity of the actual marine propulsion systems leads to the development of dedicated control functions, according to special requirements. In order to test performance and reliability of the propulsion control logics, new design approaches for the marine automation design should be introduced. With regard to this, the “Real Time Hardware in the Loop” (RT HIL) simulation technique is becoming a standard part of the design process for the propulsion controller of the last and most important Italian naval vessels. This paper deals with some new solutions in automation design, from the RT HIL simulation benefits to the introduction of special control aspects, due to the need to manage high power engines for different propulsion conditions. In particular, the general propulsion automation schemes, analysed in this paper and proposed for high powered fast ships, are the results of the experience gained by the authors during the cooperation between Genoa University and the Italian automation provider “Seastema”, for the propulsion controllers designs of the aircraft carrier Cavour (COGAG propulsion) and FREMM Class frigates (CODLAG propulsion)
Diesel engine and propulsion diagnostics of a mini-cruise ship by using Artificial Neural Networks
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