Intelligent Selection of Main Engine at the Preliminary Design Stage of Ships

1995 ◽  
Vol 11 (04) ◽  
pp. 245-251
Author(s):  
Dongkon Lee ◽  
Kyung-Ho Lee ◽  
Soon-Hung Han

The propulsion system is one of the most complicated systems in a ship and its performance greatly depends on the selection of the main engine. Also, the propulsion system occupies a large portion of the total shipbuilding cost, as well as a large portion of the annual operating cost in fuel consumption. Selecting the right propulsion system is an important factor consideration for shipowners and designers. In the preliminary stage of ship design, the main engine is selected by a design expert and this usually is a difficult task for a novice designer. With the help of a design support system, efficiency in selecting the right engine can be increased. In this study, a knowledge-based system for engine selection which can be used in the preliminary design stage for a merchant ship has been developed. The knowledge base is constructed using heuristic knowledge acquired from design experts. Two databases of engine catalogs and of existing ships are also constructed. Various performance prediction modules of the domain of naval architecture are integrated with the knowledge bases and databases. To enhance the user interface, a graphical user interface (GUI) built upon the Motif widgets is adapted.

2009 ◽  
Vol 9-10 (1) ◽  
pp. 35-44
Author(s):  
Charchalis Adam ◽  
Krefft Jerzy

Economizer Selection Method with Reference to its Reliability at Preliminary Design Stage of Seagoing Vessels The economizers are used for production of steam heating on en route ships. The economizers are producing steam in a heat exchange process from the ship's main engine exhaust gas. Products of the incomplete combustion of the heavy fuel oil remaining in engines, passing the boiler, collect on the heat exchange surface of the economizer. When the incorrect assumptions are made for the boiler operation conditions, the boiler steam capacity drops and fire and burning of the incomplete combustion products can occur in the economizer. To minimize combustion product quantity that collects on the boiler surface, the allowable exhaust gas pressure drop in the boiler should be taken into consideration, as well as the results from recommended exhaust gas flow velocity that is determined by main engine service load determined in the preliminary design phase of the ship. The remaining operating conditions are made in such a way to obtain high steam capacity of the boiler. It is essential at the design stage to take into consideration the future operating parameters of the combustion-steam-water installation, since these parameters depend on the choice of boiler and determined at the design stage production of steam. On the basis of operation parameters of contemporary container ships, an attempt was made to select economizer capacity in the preliminary design stage taking into consideration operation conditions of the propulsion system-steam installations unit in aspect of economizer reliability.


Author(s):  
T. A. Osman

It has been realized that attenuation of the noise radiated from diesel engine generating sets is a challenge for the designer. The enclosure, which may be designed for noise reduction, has to allow for the flow of the necessary amount of air. The present work is an attempt to tackle such a contradictory problem. A mathematical model is developed to predict the enclosure design configuration. The parameters affecting the insertion loss, such as enclosure and silencer dimensions, number of baffles, and sound absorption material specifications are taken into account. To verify the developed model, experimental measurements based on ISO 8528 part 10 are conducted. Four different generating sets covering a wide range of power rating are employed. The effect of changing each parameter on the insertion loss is studied separately for the chosen range. Design charts, based on the results of the present investigation, are constructed to facilitate the section of a proper acoustical enclosure configuration at the preliminary design stage.


1976 ◽  
Vol 3 (1) ◽  
pp. 138-155
Author(s):  
Joseph Penzien

The complete seismic design process of certain important structures based on time-history dynamic analyses is traced from the initial preliminary design stage through the final stage of predicting lifetime performance to strong motion earthquakes. Emphasis is placed upon (1) selection of sound design procedures, (2) consideration of field and laboratory evidence, (3) application of present day knowledge, and (4) recognition of uncertainties involved in the complete process. It is concluded that meaningful predictions of performance can be made only when formulated in a probabilistic sense.


Structures ◽  
2021 ◽  
Vol 31 ◽  
pp. 395-405
Author(s):  
Arsalan Alavi ◽  
Elena Mele ◽  
Reza Rahgozar ◽  
Ehsan Noroozinejad Farsangi ◽  
Izuru Takewaki ◽  
...  

1999 ◽  
Vol 36 (03) ◽  
pp. 171-174
Author(s):  
Hüseyin Yilmaz ◽  
Abdi Kükner

It is well known that stability is the most important safety requirement for ships. One should have some information on ship stability at the preliminary design stage in order to reduce risk. Initial stability of ships is an important criterion and can be closely evaluated in terms of form parameters and vertical center of gravity. In this study, using some sample ship data, approximate formulations are derived by means of regression analysis for the calculations expressed in terms of ship preliminary design parameters that can easily provide approximate GM calculations. Thus designers can be provided with ship stability at the preliminary design stage, and also a set of appropriate design parameters for improving vessel stability can easily be determined.


2021 ◽  
Author(s):  
Sacheen Bekah

This thesis presents the use of Finite Element (FE) based fatigue analysis to locate the critical point of crack initiation and predict life in a door hinge system that is subjected to both uni-axial and multi-axial loading. The results are experimentally validated. The FE model is further used to obtain an optimum design per the standard requirement in the ground vehicle industry. The accuracy of the results showed that FE based fatigue analysis can be successfully employed to reduce costly and time-consuming experiments in the preliminary design stage. Numerical analysis also provides the product design engineers with substantial savings, enabling the testing of fewer prototypes.


2021 ◽  
Author(s):  
Sacheen Bekah

This thesis presents the use of Finite Element (FE) based fatigue analysis to locate the critical point of crack initiation and predict life in a door hinge system that is subjected to both uni-axial and multi-axial loading. The results are experimentally validated. The FE model is further used to obtain an optimum design per the standard requirement in the ground vehicle industry. The accuracy of the results showed that FE based fatigue analysis can be successfully employed to reduce costly and time-consuming experiments in the preliminary design stage. Numerical analysis also provides the product design engineers with substantial savings, enabling the testing of fewer prototypes.


2015 ◽  
Vol 22 (1) ◽  
pp. 28-35
Author(s):  
Katarzyna Żelazny

Abstract During ship design, its service speed is one of the crucial parameters which decide on future economic effects. As sufficiently exact calculation methods applicable to preliminary design stage are lacking the so called contract speed which a ship reaches in calm water is usually applied. In the paper [11] a parametric method for calculation of total ship resistance in actual weather conditions (wind, waves, sea current), was presented. This paper presents a parametric model of ship propulsion system (screw propeller - propulsion engine) as well as a calculation method, based on both models, of mean statistical value of ship service speed in seasonal weather conditions occurring on shipping lines. The method makes use of only basic design parameters and may be applied in preliminary design stage.


1995 ◽  
Vol 11 (04) ◽  
pp. 252-263
Author(s):  
Walter L. Christensen ◽  
Philip C. Koenig

Standard outfit package units for reverse osmosis plants, fire pumps, steering gear, and sanitary spaces were proposed for the LPD 17 amphibious transport dock ship design. The ship was in the preliminary design stage, and it was necessary to determine how this shift to outfit modularity would affect the ship procurement program. Because the use of package units would not have a significant impact on the overall characteristics and performance of the ship, the focus of the investigation was on material ordering and production scheduling. The analysis took account of zone-area-stage outfitting methods and also more traditional practices. With either approach, it was found that the package units did not present any schedule or procurement problems This particular study was focused on a very specific issue, but the approach is applicable to a wide range of production impact assessment problems.


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