Turbulent flow field and resulting noise induced by hub-less propellers

无轮毂螺旋桨引起的湍流场和噪声

• 批准号: 275329378
• 负责人: Professor Dr.-Ing. Otto von Estorff
• 金额: --
• 依托单位: Institut für Modellierung und Berechnung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/275329378?language=en
• 关键词: Turbulent; flow; field; resulting; noise

The underwater noise which is generated by ship propulsion systems becomes a more and more growing environmental problem nowadays. A new promising design concept for the reduction of emitted underwater noise is the usage of hub-less propellers in conjunction with an electrical ring drive. Detailed research with respect to this new propulsion system, especially in terms of the turbulent flow field in and behind a hub-less propeller and the resulting sound field, has not been carried out so far. Main focus of the proposed project will be the investigation of the overall topology of the wake flow, the transition and collapse of the tip vortices, the topology of the horseshoe vortices at the blade hub and the radiated hydro acoustic sound field. Time resolved stereo PIV experiments in the wake flow of a hub-less propellers and time synchronous measurements of the fluctuating surface pressure in combination with fully transient DES computations of the turbulent flow field will be core elements of the planned research work.For the numerical prediction of the hydro-acoustic pressure field a fourth order Expansion over Incompressible Flow (EIF) approach will be developed based on a finite volume formulation. The approach for the analysis of the experimental data, numerical data and for the identification of coherent flow structures will be the Proper Orthogonal Decomposition procedure (POD). Moreover it will be complemented with vortex core extraction methods. Due to the usage of the POD method, conclusions to the acoustics of different coherent flow structures will be possible for the first time. In the outlook of this project, first design rules for the reduction of hydro-acoustic sound emissions might be reasoned.

船舶推进系统产生的水下噪声是当今日益严重的环境问题。减少水下噪音的一个新的有希望的设计概念是将无轮毂螺旋桨与电动环驱动器结合使用。关于这种新的推进系统，特别是关于无轮毂螺旋桨内部和后面的湍流流场以及由此产生的声场的详细研究，到目前为止还没有进行过。该项目的主要重点将是研究尾迹流的总体拓扑结构、叶尖涡的过渡和坍塌、叶片轮毂处马蹄涡的拓扑结构和辐射水声声场。无轮毂螺旋桨尾迹流的时间分辨立体声PIV实验和脉动表面压力的时间同步测量以及湍流流场的全瞬变DES计算将是计划中的研究工作的核心内容。为了数值预测水声压力场，将发展基于有限体积公式的四阶不可压流展开(EIF)方法。分析实验数据、数值数据和识别相干流动结构的方法将是适当的正交分解程序(POD)。此外，它将与涡核提取方法相辅相成。由于POD方法的使用，将首次有可能得出不同相干流动结构的声学结论。从这个项目的前景来看，减少水声发射的第一个设计规则可能是合理的。