Objectives and content
When specifying marine propulsion units for new ships, the standard practice of today is to rely on power requirements for calm water ship resistance, usually obtained through model tests in a towing tank, adding empirical "service" margins to cover possible inflation in power demand during operation. Ship delivery trials which verify the above choices, are also conducted in calm waters. Thus, the first time the marine engine is loaded under steady conditions off-design point, but also under dynamic conditions, is when the ship is on her first voyages in heavy weather. In ship operation under such severe conditions, trying to avoid potentially dangerous overloading, may result in powerplant underutilisation and costly delays. This situation becomes more pronounced with modern highly rated engines.
The objectives of the ACME project are:
- to develop methods enabling examination of the dynamic behaviour of the propulsion installation in advance, during the ship design stage - to develop engine adaptive control schemes and governor algorithms allowing maximum exploitation of powerplant capabilities in all ship operating conditions
- to verify the methods and schemes by full scale ship-board testing
The approach will be to consider the dynamic behaviour of all the units in the propulsion system and especially the intimate coupling of the hull-propeller-engine-turbocharger units. Systematic self-propelled ship model tests in waves will be conducted, the results of which will enable the building of improved mathematical models for the transient behaviour of these units. Then, the engine dynamic and thermodynamic behaviour will be examined using advanced computer simulation techniques. Appropriate engine control schemes will be proposed and these will be examined initially using simulation models of the propulsion system. Such advanced control schemes will involve electronic governor algorithms, variable engine settings and turbocharger control. Promising schemes will be tested in prototype form on large marine engines on the test bed. Finally, full-scale long-term experiments on a newbuild containership, during normal trading conditions including heavy weather operation, will validate the results of the model tests, as well as verify the competency of the selected control schemes.
A revised methodology for powerplant specification in newbuildings will be proposed and recommendations of powerplant usage will be put forward, to account for operation off-design and in dynamic conditions Appropriate procedures will be proposed for retrofitting existing ships to use the proposed engine adaptive control schemes. Recommendations will also be made for improved standard test procedures to be applied in ship model tests, engine shop trials and ship delivery trials.
It is expected that the results of the ACME project will lead to improved utilization of the operating envelope of marine powerplants, resulting in increased operability, improved long-term efficiency hence reduction global pollution and improved ship safety in all weather conditions.
The consortium comprises of a marine engine manufacturer (MAN-B&W), a turbocharger manufacturer (ABB), a propeller manufacturer (LIPS), a ship model basin operator (HSVA), a University Laboratory Marine Engineering (NTUA/LME) and a shipping company (DANAOS) which is leading the consortium as an end-user of the developed technology.
Funding SchemeCSC - Cost-sharing contracts
2450 København Sv
5150 BB Drunen