Collaborative Research: "An Adaptive hp-Finite Element Method for Two-Fluid Flows with Topological Change"

合作研究：“拓扑变化的两流体流动的自适应 HP 有限元方法”

• 批准号: 0513433
• 负责人: Luigi Martinelli
• 金额: --
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-15 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0513433&HistoricalAwards=false
• 关键词: Collaborative; Research; Adaptive; hp; Finite

The investigators propose a methodology for performing highly resolved simulations of multi-fluid flow problems with topological change. The methodology combines a mesh deformation and adaptation algorithm and an hp-finite element method to obtain high spatial accuracy. Multi-scale resolution is provided by using a mesh refinement criterion that detects oncoming topological change and automatically refines the mesh. To allow topology change (reconnection of fluid interfaces), a level-set formulation is used in a small spatial and temporal window around the topology change event. Once the topology change is complete, the window is removed and the high-accuracy deforming mesh simulation is continued. This approach will provide better accuracy and efficiency than previously possible for multi-fluid problems with topological change. The techniques developed can also be used with formulations such as molecular dynamics for the topological change window and thus they are the step towards a first-principles prediction of practical problems with topological change.Examples of flows having topological change include wave crashing, cavitation, bubbly flows, boiling, atomization, mold-filling, liquid jets in a gas, coating flows, etc. The design of many practical devices hinges on an accurate prediction of these flows. One such example is liquid fuel injection into either jet engines or internal combustion engines. The performance of these devices is strongly dependent on the performance of the fuel injectors. (Most people are familiar with the idea of getting their automobile fuel injectors cleaned to increase efficiency and reduce pollutant production). Injectors are currently designed almost entirely using a trial and error approach because current analytical and numerical tools cannot predict the process. This investigation aims to develop a simulation technique that will provide accurate and reliable predictions of practical flows having topological change.

研究人员提出了一种对拓扑变化的多流体流动问题进行高分辨率模拟的方法。 该方法结合了网格变形和自适应算法以及 HP 有限元方法来获得高空间精度。 通过使用网格细化标准来提供多尺度分辨率，该标准检测即将到来的拓扑变化并自动细化网格。 为了允许拓扑变化（流体界面的重新连接），在拓扑变化事件周围的小空间和时间窗口中使用水平集公式。 拓扑更改完成后，窗口将被移除，并继续高精度变形网格模拟。 对于拓扑变化的多流体问题，这种方法将比以前提供更好的精度和效率。 所开发的技术还可以与拓扑变化窗口的分子动力学等公式一起使用，因此它们是朝着拓扑变化实际问题的第一性原理预测迈出的一步。具有拓扑变化的流动的例子包括波碰撞、空化、气泡流、沸腾、雾化、模具填充、气体中的液体射流、涂层流动等。许多实际设备的设计取决于对这些拓扑变化的准确预测。 流动。 其中一个例子是将液体燃料喷射到喷气发动机或内燃机中。 这些装置的性能很大程度上取决于燃油喷射器的性能。 （大多数人都熟悉清洁汽车燃油喷射器以提高效率并减少污染物产生的想法）。 目前喷射器的设计几乎完全采用试错法，因为当前的分析和数值工具无法预测该过程。 这项研究旨在开发一种模拟技术，为具有拓扑变化的实际流动提供准确可靠的预测。