EFD and CFD for KCS heaving and pitching in regular head waves

The KCS container ship was investigated in calm water and regular head seas by means of EFD and CFD. The experimental study was conducted in FORCE Technology’s towing tank in Denmark, and the CFD study was conducted using the URANS codes CFDSHIP-IOWA and Star-CCM+ plus the potential theory code AEGIR. Three speeds were covered and the wave conditions were chosen in order to study the ship’s response in waves under resonance and maximum exciting conditions. In the experiment, the heave and pitch motions and the resistance were measured together with wave elevation of the incoming wave. The model test was designed and conducted in order to enable UA assessment of the measured data. The results show that the ship responds strongly when the resonance and maximum exciting conditions are met. With respect to experimental uncertainty, the level for calm water is comparable to PMM uncertainties for maneuvering testing while the level is higher in waves. Concerning the CFD results, the computation shows a very complex and time-varying flow pattern. For the integral quantities, a comparison between EFD and CFD shows that the computed motions and resistance in calm water is in fair agreement with the measurement. In waves, the motions are still in fair agreement with measured data, but larger differences are observed for the resistance. The mean resistance is reasonable, but the first order amplitude of the resistance time history is underpredicted by CFD. Finally, it seems that the URANS codes are in closer agreement with the measurements compared to the potential theory.     

西门子公司的研究与开发工作

介绍西门子公司研究与开发的工作范围、组织形式等。     

Violation or strengthening of the self-financing doctrine at international airports by SMCP funded PPP schemes?

International airports are among the few examples of transport infrastructures which can well achieve self-financing. The growing interest of private companies in airport construction and operation is the visible testimony to this fact. However, the financing structures of airports are complex, involving not only traffic, passenger and goods handling, but also non-aviation services, such as retail, car parking or intermodal facilities. The integration of social marginal cost pricing schemes into this organizational structure according to the strategic plans of the European Commission, however, is challenging. This paper investigates whether they comply with a second strategic policy objective at European and national level, which is to foster public-private partnerships (PPPs) in transport financing in terms of full cost coverage, risks and incentives.The cases analysed in this paper deal with two sites with very different characteristics: Munich Airport which has been publicly operated since 1991 and the Bulgarian airports Varna and Burgas, which have been managed since 2007 by one concessionaire and whose planning and future development is being accomplished with private capital. The results of both cases showed that self-financing is possible in case congestion costs are considered in the SMCP schemes, and given that air traffic growth rates return to the significant levels prior to the economic crisis. The chapter will discuss the legal implications of congestion pricing at European airports which are violating current EC legislation, as well as the impact of alternative pricing schemes on the environmental performance and technological innovation in aviation.     

Virtual mobility and organizational reality – a note on the mobility needs in knowledge organisations

This article addresses the potential for reducing international work-related air travelling through the use of information and communication technologies such as videoconferences and e-learning in knowledge companies. It looks at the potential for reducing travel related to such things as meetings and teaching. In the absence of regulations, however, we do not find potential for reducing the number of trips of this type because they do not facilitate face-to-face contacts. Therefore the conclusion is, that policy and planning have to look for other options for pursuing ‘sustainable mobility’ policies in the future.