Multi-component cavitation modelling for the numerical flow simulation of real fluid mixtures in hydraulic systems

用于液压系统中真实流体混合物数值流动模拟的多分量空化建模

• 批准号: 355240670
• 负责人: Professor Dr.-Ing. Romuald Skoda
• 金额: --
• 依托单位: Lehrstuhl für Hydraulische Strömungsmaschinen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/355240670?language=en
• 关键词: Multi; component; cavitation; modelling; numerical

In hydraulic systems, usually complex fluid mixtures e.g. hydraulic oils or fuels are utilized. These mixtures consist of several hundred distinct components whose fluid and transport properties depend on the local mixture composition. It is assumed that for bubble dynamics and cavitation, in dependence on environmental conditions around the bubble, a local fuel segregation of the light and heavy volatile components within as well as around the bubble occurs, similar to droplet evaporation. Recent CFD methods use cavitation models that do not account for this segregation. Therefore, they reflect the occurrence of cavitation e.g. in fuels only insufficiently. The aim of the proposed project is the development of a multi component single bubble dynamics model that describes the heat and mass transfer as well phase change of spherical bubbles component-wise and therefore captures the fluid mixture segregation. Simple fluid mixtures are treated with a discrete model and real mixtures as e.g. fuels by a multi component model based on continuous thermodynamics. Furthermore, the interaction between air release and absorption with cavitation in multi-component fluid mixtures is modelled. The validation and application is performed on test cases which are representative for injection and oil hydraulic systems. In a first step, even the application of the multi-component single bubble model serves for a better understanding of the cause and effect chain between fluid mixture, bubble dynamics, air release and cavitation erosion. In a second step, it is aimed at a subsequent project with the focus on multi component cavitation modelling for 3D CFD.

在液压系统中，通常复杂的流体混合物，例如使用液压油或燃料。这些混合物由几百个不同的成分组成，其流体和运输特性取决于局部混合物组成。假定对于气泡动力学和空化，依赖气泡周围的环境条件，这是在气泡内以及气泡周围发生的局部燃料隔离，类似于液滴蒸发。最近的CFD方法使用的空化模型无法解释这种隔离。因此，它们反映了空化的发生，例如在燃料中仅不足。拟议项目的目的是开发多组分单个气泡动力学模型，该模型描述了球形气泡成分的热量和质量转移以及相变的相变，因此捕获了流体混合物的分离。简单的流体混合物用离散模型和真实混合物进行处理，例如通过基于连续热力学的多组分模型燃料。此外，对多组分流体混合物中空气释放与空化的吸收之间的相互作用进行了建模。验证和应用是对代表注射和油液压系统的测试用例进行的。第一步，即使是多组分单个气泡模型的应用也可以更好地理解流体混合物，气泡动力学，空气释放和气蚀侵蚀之间的因果链。在第二步中，它针对后续项目，重点是3D CFD的多组件空化建模。