基于散货船的几何参数和速度,在迎浪条件下,其增加的汹涛阻力系数近似研究外文翻译资料

 2021-12-12 09:12

英语原文共 8 页

APPROXIMATING THE ADDED RESISTANCE COEFFICIENT FORA BULK CARRIER SAILING IN HEAD SEA CONDITIONS BASEDON ITS GEOMETRICAL PARAMETERS AND SPEED

基于散货船的几何参数和速度,在迎浪条件下,其增加的汹涛阻力系数近似研究

Tomasz Cepowski, Prof.

Maritime University of Szczecin, Poland

Tomasz Cepowski,教授。

波兰什切青海事大学

ABSTRACT:The article presents the mathematical function to calculate the added wave resistance transfer function for bulk carriers. Based on this function, the statistical mean added wave resistance generated by an irregular head wave with arbitrary statistical parameters can be forecasted. The input parameters are: waterplane area, waterplane coefficient,ship speed, and frequency of the regular wave. The model has been developed based on the theory of artificial neural networks. The presented function can be used in design analyses, and for planning shipping routes in situations when basic geometrical parameters of the hull are only available and not the full technical documentation. The article presents sample cases of use of this function to calculate the added wave resistance transfer function and the statistical mean added wave resistance..Another presented application refers to waterplane coefficient optimisation taking into account the added wave resistance at the stage of preliminary bulk carrier design.

摘要:本文介绍了一个计算散货船增加的波阻传递的数学函数。基于该函数,可以预测由具有任意统计参数的不规则迎浪产生的统计平均附加波阻。输入参数为:水面面积,水面系数,船速和规则波频率。该模型是基于人工神经网络理论开发的。所提供的功能可用于设计分析,也可用于仅有船体基本几何参数而没有完整技术资料的运输路线规划的情况。本文介绍了使用该函数计算增加的波阻传递函数和统计平均加波阻力的示例。另外应用于涉及水平面系数优化,其考虑了在初步散货船设计阶段的附加波阻。

Keywords: bulk carrier; resistance; added wave resistance; added resistance coefficient; regular wave; irregular wave; ship designing; preliminary design stage; artificial neural networks; approximation; forecasting; speed; waterplane area; waterplane coefficient, sample case, task, designing.

关键词:散货船;抵抗性;增加波阻;增加阻力系数;规则波;不规则波;船舶设计;初步设计阶段;人工神经网络;近似;预测;速度;水面面积;水线系数,样本案例,任务,设计。

INTRODUCTION

Assumptions concerning the design of a floating objectdesigned for arbitrary purposes usually include two basicgroups of requirements, which are [9]:

介绍

关于为任意目的设计的浮动物体的设计假设通常包括两组基本要求,即[9]:

bull; economic requirements,

bull; technical requirements.

bull; 经济要求,

bull; 技术要求。

Meeting the first group of requirements usually means realisation of ship function at minimal financial costs of building and maintenance of the object, while meeting the other group is equivalent to objectrsquo;s ability to keep afloat and possess other technical features which will secure safety of the performed operations. To meet the above requirements, aso-called design goal and design constraints are formulated.

满足第一组要求通常意味着以最小的建造费用和维护成本来实现船舶功能,而满足另一组要求则相当于船舶保持漂浮的能力并具有其他技术特征以确保所执行操作的安全性的能力。为了满足上述要求,制定了所谓的设计目标和设计约束。

For bulk carriers, the design goals are mainly the result of the transport study. Basic design goals for the bulk carrier refer to:

对于散货船,设计目标主要是运输研究的结果。散货船的基本设计目标是指:

1. mass of the cargo to be transported,

2. operating speed of the ship, shipping route, and the distance between transhipment ports.

1. 大量需要要运输的货物,

2. 船舶的营运航速,运输路线以及转运港口之间的距离。

Reaching the assumed operating speed by the bulk carrierdepends, among other factors, on operating parameters andconditions of the propulsion system, the efficiency of thepropulsion system and hull, and the total hull resistance.

除了其他因素之外,通过散货船达到假设的营运航速取决于推进系统的运行参数和条件,推进系统和船体的效率以及船体的总阻力。

Among other components, the total hull resistance includes

the added wave resistance, which:

bull; is connected with ship navigation in storm waves,

bull; can contribute to about 30-50% of total ship resistance,

bull; leads to remarkable drop of operating speed,

bull; depends on, among other factors, hull dimensions andshape.

船体的总阻力所包含的附加的波浪阻力,有这些成分:

bull; 与风暴波中的船舶导航有关,

bull; 占比约30-50%的总船舶阻力,

bull; 导致运行速度显着下降,

bull; 除其他因素外,还取决于船体尺寸和形状。

That is why forecasting the added wave resistance of the ship is a considerable challenge for ship designers, due to economic aspects of selection of ship propulsion parametersand assessment of fuel consumption and time of voyage, as well because of the need to improve energy efficiency of ship operation.

这就是为什么由于选择船舶推进参数和评估燃料消耗和航行时间的经济方面,预测船舶增加的波浪阻力对船舶设计者来说是一个相当大的挑战,因为需要提高船舶运营的能源效率。

Forecasting the added wave resistance is also an important element of various shipping route planning systems. When the detailed data on ship resistance-propulsion characteristics taking into account the added wave resistance and hull geometry are missing, these characteristics are to be forecasted using simplified methods.

预测增加的波浪阻力也是各种航线规划系统的重要元素。当考虑到增加的波阻和船体几何形状的船舶阻力 - 推进特性的详细数据缺失时,这些特征将使用简化的方法进行预测。

(1)THE ADDED WAVE RESISTANCE

Accounting methods used to assess the added wave resistance are limited to resistance calculations for the head wave. These methods base on the assumption that the added resistance has the nature of wave resistance and does not depend on the calm water resistance. The mean added wave resistance is calculated using the function which initially describes the resistance contribution from a regular (sine)wave, R AW (omega;E ). Then, applying the superposition principle to the spectral distribution of the irregular wave (given by function Szeta;zeta; (omega;E)), the increase of the statistical mean resistanceRw in irregular (statistical) wave is calculated as:

(omega;E) (1)

where:

Rw – statistical mean wave resistance increase,

RAW – added resistance from the regular wave,

omega;E – encounter frequency of the harmonic wave,

zeta;a – amplitude of the regular wave,

Szeta;zeta; – wave energy spectrum density function.

(1)增加的波浪阻力lt;

资料编号:[5655]

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