共查询到19条相似文献,搜索用时 93 毫秒
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实际海浪环境中舰船大尺度模型试验研究进展 总被引:1,自引:0,他引:1
目前对舰船总体性能的研究主要是依靠数值计算、水池模型试验、实际海浪环境大尺度模型试验以及实船海试等方法,以上各种方法均有一定的适用范围.实际海浪环境中舰船大尺度模型试验技术是采用适当缩尺比的自航船模在自然水域环境中进行的试验,可以研究舰船在开阔海域自由航行状态下的各项航行性能.分析各种舰船总体性能研究方法的优缺点,针对目前舰船总体性能理论与试验研究存在的问题分析开展舰船大尺度模型海上试验研究的必要性,综述国内外大尺度模型试验技术的发展现状,最后针对该试验技术中的关键技术及热点问题进行总结与展望. 相似文献
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舰船上层建筑是诱发舰船舰面空气湍流的主要因素,对于具有全通飞行甲板的舰船,其岛式上层建筑的外形及布置则出现了多样化的趋势,对迎风方向后方的气流场形态势必会产生影响.为了解上层建筑外形及布局形式的变化对舰船空气流场,尤其是对舰载机起降影响的初步规律,通过定常同等试验工况条件下,建立多种形式的上层建筑以及变化研究模型上层建筑纵向的布置位置的数值三维模型,对5种模型分别进行数值模拟计算,分析和观察由此产生的气流场变化,对计算结果进行取值分析.通过各模型及原型舰模型间气流场特性的对比,所得出的有关结论与目前实际的舰船产品所采用的布置形式决策是一致的. 相似文献
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为避免波浪涌入港内,沿岸港口皆构筑防波堤,堤口及通行水道不宜过宽,采用单向航行以缩小水道宽度是普遍现象。船舶进出港单向航行涉及进出顺序的安排。船舶自动识别系统(AIS)自2004年4月生效实施,提供了船舶动态、静态及航次相关信息数据,对VTS的交通组织服务而言,给予船舶通行管制莫大的帮助。为避免船舶在港口水域因为等候进出造成的拥挤招致碰撞,交管中心对于到达船舶及出港船舶必须作出适当的排序,既可解决通航安全,亦可达到通航效率。本研究就船载AIS所提供的信息中,与船舶通行安全有关的数据,以高雄港水域为例,运用AHP方法作成权重因素分析,其结果可作为运用于整合性船舶交通组织模型研究的参考。 相似文献
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《船舶与海洋工程学报》2021,(3)
This paper proposes a semi-empirical model to predict a ship's speed loss at arbitrary wave heading.In the model,the formulas that estimate a ship's added resistance due to waves attacking from different heading angles have been further developed.A correction factor is proposed to consider the nonlinear effect due to large waves in power estimation.The formulas are developed and verified by model tests of 5 ships in regular waves with various heading angles.The full-scale measurements from three different types of ships,i.e.,a PCTC,a container ship,and a chemical tanker,are used to validate the proposed model for speed loss prediction in irregular waves.The effect of the improved model for speed loss prediction on a ship's voyage optimization is also investigated.The results indicate that a ship's voyage optimization solutions can be significantly affected by the prediction accuracy of speed loss caused by waves. 相似文献
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The mathematical modeling group (MMG) model is well known and is widely used in the field of ship maneuverability. However,
the MMG model can be applied only after determination of the hydrodynamic coefficients either from comprehensive captive model
tests or from general empirical data. Around the cruising speed, when a ship's drift angle is relatively small, several methods
have been developed to predict hydrodynamic coefficients from the ship's principal particulars, e.g., Kijima's method. Kijima's
method is efficient in predicting the ship's maneuverability at the initial design stage and is even able to assess the effect
of changes in stern design. Similarly, for the low speed range when a ship's drift angle is relatively large, several methods
for predicting the ship's hydrodynamic coefficients have been proposed, based on captive model tests, such as those by Kose,
Kobayashi, and Yumuro. However, most of the methods developed for low speeds cannot be applied to general ship types without
additional experiments being performed. In contrast, Karasuno's method uses theoretical and empirical approaches to predict
the hydrodynamic forces, even for large drift motions. Although Karasuno's model utilizes the ship's principal particulars
and is applicable to a general vessel, it has not been widely used. This is because the form of Karasuno's model is relatively
complicated and its accuracy around the cruising speed is less than that for other methods that have been specifically developed
for the cruising speed range. A practical method for predicting hydrodynamic forces for the entire operating speed range of
blunt-body ships is proposed in this article. It is based on the MMG model and predicts hydrodynamic coefficients based on
a ship's principal particulars. A regression model for the proposed method has also been proposed by analyzing 21 different
blunt-body ships. Finally, simulations of a very large 4-m crude carrier (VLCC) model using the proposed method were carried
out and the results compared with free-running experiments (both at the cruising speed and at low speeds) to validate the
efficacy of the model. 相似文献
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The prediction of a ship's resistance especially the viscous wave-making resistance is an important issue in CFD applications. In this paper, the resistances of six ships from hull 1 to hull 6 with different hull forms advancing in still water are numerically studied using the solver naoe-FOAM-SJTU, which was developed based on the open source code package OpenFOAM. Different components of the resistances are computed and compared while considering two speed conditions(12 kn and 16 kn). The resistance of hull 3 is the smallest while that of hull 5 is the largest at the same speed. The results show hull 3 is a good reference for the design of similar ships, which can provide some valuable guidelines for hull form optimization. 相似文献
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船舶碰撞责任的计算机辅助判析技术研究 总被引:1,自引:1,他引:0
探索船舶碰撞事故责任的计算机辅助判析技术,以弥补划分碰撞责任比例的支撑数据不充分。建立了适于裁决雾中船舶碰撞责任比例的知识体系,包括基于船舶行为以排除人为因素干扰,兼用于高速船的避让区界的新规则。提出了地自动处理任何船舶碰撞责任比例的模型。解决了船舶单项行为有无过失的定性问题及失量的计算机智能化确定问题。系统经实例试用,在合理性,快速性,经济性方面已初显优势。 相似文献