深海系泊浮体物面非线性时域耦合动力分析

文章基于三维时域势流理论和弹性细长杆理论,研究并提出了深海系泊浮体物面非线性时域耦合动力分析方法。该方法采用时域物面非线性理论方法在瞬态位置直接时域模拟系泊浮体所需水动力,结合有限元方法计算系泊缆索的动力响应,利用异步耦合方法实现浮体和系泊缆索的时域耦合动力求解。既满足系泊浮体时域水动力耦合,又满足系泊浮体和系泊缆索动力耦合。通过对二阶非线性不规则波作用下深海系泊半潜式平台的时域耦合响应特性进行研究,将不同海况下物面非线性时域耦合静力响应和动力响应与间接时域耦合动力响应的三种方法计算结果进行比较。研究结果表明,系泊缆索动力响应明显,平台瞬态空间位置对垂荡低频运动影响较大,有必要在平台瞬时湿表面采用动力响应方法进行深海系泊浮体时域耦合响应分析。     

波浪中航行两船模池壁干扰效应的数值研究

对规则波中顶浪并行航行的两船模,基于频域移动脉动源格林函数建立了有效表达池壁效应的三维数学模型,该模型采用分布源积分方法求解近距航行两船模的波浪作用力和运动响应,并利用镜像原理将水池格林函数表示为开阔水域的格林函数和由镜像点源组成的无穷级数.分析移动脉动源格林函数的远场传播模态及其特性可知,当τ>0.272(τ为斯特劳哈尔数)时各传播波模态均不在点源的上游出现,故此时点源波系的影响范围可由环形—扇形波的半楔角确定,在此基础上计及船模辐射—绕射波的池壁反射作用对自身和另一船模的干扰,依据船型要素、水池宽度和两船相对位置,采用六个几何临界半楔角表征船体的辐射—绕射波,提出了并行航行两船模的池壁效应判别方法.数值研究表明:不同镜像次数下水池格林函数的数值差异主要体现在距船艏较远处,在兼顾计算精度与效率的原则下可选取有限项级数的水池格林函数作为积分内核,而池壁效应对近距航行两船运动响应的影响主要体现在长波区.     

船舶上浪预报中甲板上浪的统计分析

本文从船艏和波面的垂向相对运动预报出发，从统计意义上给出表征上浪严重程度的甲板上浪的定量分析，进而为预报敞口集装箱船进水量提供依据。在止浪延续时间的分布函为九计算中了以往的计算方法。     

Study of algorithms of new slender ship theory of wave resistance

In this paper, Noblesse‘s New Slender-Ship Wave-Making Theory was investigated numerically. Detailed expressions of zeroth and 1st order wave resistance have been derived and calculation programs have also been compiled. In the single and double integral terms of Green function, the kernel function of wave resistance expression, special function expansion method and Chebyshev polynomials approach have been adopted respectively, which greatly simplify the calculation and increase the convergence speed.     

Reducing speed and fuel transfer of the Green Flag Incentive Program in Kaohsiung Port Taiwan

This research applied the Green Flag Program to assess the benefits of reducing speed and fuel transfer for large merchant vessels (bulk and container) entering Kaohsiung Port. This study adopts an activity-based model to calculate fuel consumption and emissions, as well as setting up two scenarios, (1) decrease vessel speed to 12 knots 20 nm away from port; and (2) decrease vessel speed to 12 knots and transfer fuel 20 nm away from port, which based on the Green Flag Program in Long Beach, in the U.S. The findings are (1) In scenario one, the container and bulk vessels saw reductions in CO₂ emissions of about 41% and 14%, respectively. In scenario two, container and bulk vessels had reductions of about 48% and 43% in SO₂ emissions, respectively. (2) Large vessels are more environmentally friendly than small vessels. (3) Using the CATCH model to assess the effectiveness of the two scenarios, it was found that container vessels benefited from both reducing speed and fuel transfer, while bulk carriers only did so from the former.     

Developing environmentally sustainable logistics: Exploring themes and challenges from a logistics service providers’ perspective

The purpose of this paper is to explore themes and challenges in developing environmentally sustainable logistical activities.The approach is explorative with a cross sectional design that takes advantage of ten case studies out of selected logistics service providers (LSPs) operating primarily in the Scandinavian countries.The findings illustrate the major themes by analyzing current and future activities in developing environmentally sustainable logistical activities. In addition, four categories of challenges are identified: customer priorities, managerial complexity, network imbalance, and technological and legislative uncertainties. It is concluded that there is a great need for a holistic perspective where LSPs and product owners together analyze and design future logistical setups.The suggested holistic and integrative model, building on a three-dimensional concurrent engineering framework, provides new opportunities for research. Further research is needed to improve the interrelationship between LSPs and their customers in the development of sustainable logistical solutions.This paper puts forward recommendations for the sustainable development of logistics by combining the results from the case studies with a review of related literature. This will be beneficial for managers and policy makers when they approach sustainable logistical challenges. The emergence and synthesis of themes and challenges are critical for a sustainable society.     

Green port project scheduling with comprehensive efficiency consideration

ABSTRACT

Ports are an important driving force for world economic growth, but they consume considerable energy. The marine sector has proposed the development of green ports to achieve low-carbon sustainable development. This paper presents a green project scheduling model of port construction to optimize comprehensive economic and environmental efficiency. Various realistic constraints are considered, including investment scale, energy savings, emissions reduction, and project priority. Comprehensive efficiency involves cost reduction, energy savings, emissions reduction, and other efficiency goals. The problem is formulated as an integer program and is solved using CPLEX in a general algebraic modeling system (GAMS). We use a representative port in China as a case port in solving its green project scheduling. The results show that the port can save 6,527 tons of standard coal, reduce 40,875 tons of CO₂, and save 49 million yuan per year in the five-year implementation period. The payback in investing in these green projects is less than six years. From an economic and environmental perspective, the comprehensive efficiency achieved is significant.     

Personalised feedback and eco-driving: An explorative study

Conventional road transport has negative impact on the environment. Stimulating eco-driving through feedback to the driver about his/her energy conservation performance has the potential to reduce CO₂ emissions and promote fuel cost savings. Not all drivers respond well to the same type of feedback. Research has shown that different drivers are attracted to different types of information and feedback. The goal of this paper is to explore which different driver segments with specific psychographic characteristics can be distinguished, how these characteristics can be used in the development of an ecodriving support system and whether tailoring eco-driving feedback technology to these different driver segments will lead to increased acceptance and thus effectiveness of the eco feedback technology. The driver segments are based on the value orientation theory and learning orientation theory. Different possibilities for feedback were tested in an exploratory study in a driving simulator. An explorative study was selected since the choice of the display (how and when the information is presented) may have a strong impact on the results. This makes testing of the selected driver segments very difficult. The results of the study nevertheless suggest that adapting the display to a driver segment showed an increase in acceptance in certain cases. The results showed small differences for ratings on acceptation, ease of use, favouritism and a lower general rating between matched (e.g., learning display with learning oriented drivers) and mismatched displays (e.g., learning display with performance oriented drivers). Using a display that gives historical feedback and incorporates learning elements suggested a non-verifiable increase in acceptance for learning oriented drivers. However historical feedback and learning elements may be less effective for performance oriented drivers, who may need comparative feedback and game elements to improve energy conserving driving behaviour.     

美国《能源与环境设计先导》(LEED)评价标准对中国《绿色建筑评价标准》的启示

通过对LEED和《绿色建筑评价标准》在节地、节能、节水、节材、室内空气质量等五大项评分项要求进行对比,得出LEED中某些评分点值得我国评价体系学习,而有些不符合中国国情,不适宜在本土发展运作;提出进一步完善我国绿色建筑评价体系的建议,其发展要结合我国国情,借鉴吸收LEED评分条款才能走出一条适合自己的、有效地促进和稳步提升我国绿色建筑发展的道路。     

Effective environmental marketing of green cars: A nested-logit approach

Using market data, we assess the effectiveness of an eco-marketing campaign on purchases of ‘green’ vehicles. The eco-marketing was designed as a quasi-experiment, having one region exposed to the marketing while the other region was the control. A two-level nested-logit model consistent with utility maximization reveals the campaign had short-term positive effects on green-car sales. Results also indicate green-car buyers come from highly educated communities. Age has a positive but non-linear effect on green car sales.