On the application of nonstructural models to ship design

Article type: Research Article

Authors: Pawlowski, J.S.^{; *}

Affiliations: Ship Research Institute of the Technical University of Gdansk

Note: [*] At present Research Fellow at the Delft Ship Hydromechanics Laboratory.

Abstract: The present paper presents an attempt to deal with the problem of applying analytic models of reality in decision making processes. The problem is not unknown to ship designers and research naval architects as it is their common experience that developed algorithms such as those for ship motions are employed in ship design process for checking performance after the relevant design particulars have already been decided. In the opinion of the author the knowledge embodied in such algorithms should and can be effectively applied in the essential design process of choosing the appropriate particulars. In the paper the obstacles hindering such a use are identified by recognising the decision making process of design. The algorithms are included in a class of scientific models for which the name of structural models is used in the paper and an analysis of those models is carried out which shows their inherent inability to suit a design process. The solution to the problem is found in the identification of models specially adapted to the needs of the decision maker, for which the name of nonstructural models is employed. The process of identification of such models is discussed in general and an example of application of such a model in seakeeping is presented, which quantifies the influence of the relevant underwater ship form parameters upon the variance of relative bow motion in head waves. It is found that of those parameters waterplane area coefficient is the one of dominating importance for its effect on relative bow motion.

DOI: 10.3233/ISP-1982-2933302

Journal: International Shipbuilding Progress, vol. 29, no. 333, pp. 125-135, 1982