Drag Optimisation of Ship Shapes (DROPSS)

国际航运承担着全球90%左右的贸易运输。航运的主导作用归因于运输货物的每吨 * 公里燃料消耗低。然而，仅约4.5万至5万艘运营商船的规模就将航运的环境和经济方面纳入了许多优化工作的重点。海运污染以及大约50%的航运直接运营成本与燃料消耗有关，而燃料消耗又取决于船舶的阻力。后者在很大程度上受定常水动力作用的控制（猜测为75%），即静水中的波阻和沿着湿表面的摩擦阻力。手段，以减少这些阻力的贡献，即使是几个每mille.The目前的建议是高度赞赏的商业和环境perspectives.The的发展与一个计算框架的流体动力学形状优化的自由浮动船体暴露于不混溶的两相流。注意力仅限于基于梯度的伴随方法在无参数优化环境。重点是波和摩擦阻力在弗劳德和弗劳德数的实际利益。具体的兴趣是指（i）准确和强大的伴随两相流模型，包括（ii）包括动态浮动方面，（iii）一种新的减少伴随湍流处理和（iv）一个改进的CAD无形状参数化的部分润湿的形状受到制造限制。应用程序将集中在一个经常调查的集装箱船和钝海上供应船。结果将转移到其他海洋工程应用的优化，例如，在靠近自由表面的浪涌区收集海浪的近岸操作可再生能源设备的设计。

International shipping is responsible for the transport of around 90% of the global trade. The dominant role of shipping is attributable to the low fuel consumption per tonne*km of transported cargo. However, the mere magnitude of around 45-50 thousand operating merchant vessels puts environmental and economic aspects of shipping into the focus of many optimisation efforts. The seaborne pollution as well as approximately 50% of the direct operating costs for shipping are related to fuel consumption, which in turn is governed by the resistance of the vessel. The latter is largely controlled (75% at a guess) by steady hydrodynamic contributions, i.e. the wave drag in calm water and the friction drag along the wetted surface. Means to reduce these drag contributions, even by a few per mille, are highly appreciated from commercial and environmental perspectives.The present proposal is concerned with the development of a computational framework for the hydrodynamic shape optimisation of free-floating ship hulls exposed to immiscible two-phase flows. Attention is confined to gradient-based adjoint methods in a parameter-free optimisation environment. Emphasis is given to wave and friction drag at Froude- and Reynolds-numbers of practical interest. Specific interest refers to (i) accurate and robust adjoint two-phase flow models including (ii) the inclusion of dynamic floatation aspects, (iii) a novel reduced adjoint turbulence treatment and (iv) an improved CAD-free shape parameterization for partially wetted shapes subjected to manufacturing constraints. Applications will focus on a frequently investigated container vessel and a blunt offshore supply vessel. Results will be transferable to the optimisation of other marine engineering applications, e.g. the design of near-shore operating renewable energy devices harvesting ocean waves in the surge zone close to a free surface.