确定多用途冰区航行船舶设计特性最优值的叠加性和互换性方法

Superposition and interchangeability of design characteristics of the multipurpose ice-going ship in determining their optimum values

[目的]研究冰区船设计参数之间的相互关联性,旨在提出一种多用途冰区航行船舶性能与设计参数之间的优化方法。冰区船作为一个整体系统,其性能指标不是独立的,通过任何一个技术指标能够近似确定其他的技术指标。[方法]采用的方法是在满足设计要求的前提下,选取冰区船各项性能指标的最优值,并采用冰区船单项设计指标最优值的叠加性特性方法,因为每一项船舶技术指标既与其他的技术指标相关,也与船舶的设计参数相关,从而可以初步估算船舶其他尺度指标和设计参数的初始近似值。在初步设计阶段,确定技术指标和设计参数近似值的大致范围会有一定的误差,这些参数在后续设计阶段将进一步细化。在误差范围内对初始值进行调整不会对某个性能指标的最优值产生较大影响,初步设计阶段确定的最优值可作为进一步改善其余船舶技术指标的约束条件,从而可以进一步确定该技术指标的最优值。[结果]采用叠加性优化设计性能指标和参数时,若将初始设计阶段确定的特征参数作为后续设计阶段的设计约束,可以逐次迭代确定目标船的性能指标和参数值。[结论]首先确定船舶参数的设计范围,然后以该确定的船型参数为约束条件,可以进一步细化冰区船的设计指标。

[Objectives]This paper aims to propose an approach for optimization of the multipurpose ice-going ship characteristics and design particulars,considering methodological interdependence among these values. The ship particulars do not appear to be independent in the systemic sense,and any of the characteristics of the size could be predetermined by the definite approximation. [Methods]The methodological approach means the selecting an independent characteristic which is varied in the next for searching its optimal value on the criteria used. It is taken into account the methodological property of superposition of design characteristics as to find the optimal values of the independent design characteristics,the associated balance proportions with the rest of the ship size characteristics and the associated parametric dependences with the design particulars,that means as well determining in the initial approximation of the rest characteristics of ship size and design particulars. Since in the subsequent design stages the refinement are carried out in the narrow intervals of their variation of the approximate values of rest ship size characteristics and design particulars,which were found approximately at the initial stage,corresponding to definite inaccuracy of their approximate determination at the initial stage.The improvement of the originally found values within the inaccuracy does not exert the noticeable influence on the optimum value of the independent design characteristic,determined at the initial stage,serving as the design constraint in the improving of the values of the rest characteristics,as well as its design particulars, found approximately in determining of optimal value of independent design characteristic.[Results]The property of superposition in finding optimal design characteristics and particulars means the possibility of their independent sequential determination if the characteristics found in the previous design stages and particulars are used as the design constraints in subsequent stages.[Conclusions]Initially the characteristics of ship size are determined with the allowance of design constraints,and then the design particulars are sought,while the design constraints are found for ship characteristics.