Passive active control of cavitating flows around ship hydrofoils

船舶水翼周围空化流的被动主动控制

• 批准号: 533951202
• 负责人: Professor Dr.-Ing. Bettar Ould El Moctar
• 金额: --
• 依托单位: Institut für Schiffstechnik, Meerestechnik und Transportsysteme (ISMT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/533951202?language=en
• 关键词: Passive; active; control; cavitating; flows

Cavitation negatively affects the performance of marine propellers, rudders, pumps, and other machinery as it is one of the major sources of erosion and energy efficiency lost. In this regard, cavitation control methods can help to improve the design of propulsion, and steering devices. Passive cavitation control methods were successfully used and are the preferable choice, because of the low costs. However, the mitigation and control of cloud cavitation for severe cavitation regimes (e.g., dynamic positioning of wind offshore supply vessels) can hardly be achieved using only a passive control methods. On the other hand, using only active control methods for different cavitating regimes requires extra energy and, consequently, leads to higher costs. Therefore, a combined passive-active control methods are the preferred choice to efficiently suppress cavitation for a broad range of cavitation regimes and reduce costs. For this aim, the active control method is only used for the severe cavitation regimes, where the passive control method is not able to control cavitation. In this project, we intend to develop a passive-active control method by using miniature vortex generators placed on the hydrofoil surface and a combination of discrete quasi radial jets (water injection). First, we will extend and validate an existing multi-scale Euler-Lagrange method to take into account compressibility of the cavitating flow. Second, we will perform systematic numerical investigations using the extended multi-scale Euler-Lagrange method (based on PANS-equations). Varying the positions of the miniature vortex generators and the injection rates, the optimized configuration of the proposed control method will be determined to suppress cavitation and mitigate its negative effects. We will then perform systematic experimental investigations in our cavitation tunnel using high-speed imaging, force and pressure sensors, and hydrophones together with advanced processing procedures and data analysis methods.

汽蚀对船用螺旋桨、舵、泵和其他机械的性能产生负面影响，因为它是侵蚀和能源效率损失的主要来源之一。在这方面，空化控制方法可以帮助改进推进装置和转向装置的设计。被动空化控制方法被成功地应用，由于成本低，是较好的选择。然而，对于严重的空化状态(如海上供给船的动态定位)，仅使用被动控制方法很难实现对云空化的缓解和控制。另一方面，对于不同的空化制度，只使用主动控制方法需要额外的能量，因此导致更高的成本。因此，采用被动-主动相结合的控制方法是在大范围空化状态下有效抑制空化、降低成本的首选。为此，主动控制方法只适用于严重的空化状态，而被动控制方法不能控制空化。在这个项目中，我们打算开发一种被动-主动控制方法，利用放置在水翼表面的微型涡流发生器和离散的准径向射流(注水)的组合。首先，我们将扩展和验证现有的多尺度欧拉-拉格朗日方法，以考虑空化流动的可压缩性。其次，我们将使用扩展的多尺度欧拉-拉格朗日方法(基于PANS方程)进行系统的数值研究。通过改变微型涡流发生器的位置和喷射速率，确定了控制方法的优化配置，以抑制空化并减轻其负面影响。然后，我们将在我们的空泡隧道中使用高速成像、力和压力传感器、水听器以及先进的处理程序和数据分析方法进行系统的实验研究。