Numerical modeling of complex interfacial physics for the simulation of industrial multifluid processes

用于模拟工业多流体过程的复杂界面物理数值建模

• 批准号: 250278-2006
• 负责人: Dufour, Steven
• 金额: $ 1.38万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=362170
• 关键词: Numerical; modeling; complex; interfacial; physics

Free surface flows are a common occurrence in industrial fluid mechanics.  Many industrial processes involve the flow of several fluids in complex geometries, and therefore the evolution of the interfaces separating these fluids.  Moreover, it is common to have geometries evolving with time, which influence, sometimes in a very complex way, the dynamics of free surfaces.  For example, hydraulic turbine designers have to take into account the cavitation phenomenon.  When water, in contact with runner blades moving at high velocity, is locally submitted to a pressure drop, the dissolved air nucleates to create bubbles.  This phenomenon is similar to boiling.  The fluid flow then makes the bubbles move from low pressure to higher pressure regions.  The bubbles may then violently implode on or close to a solid surface.  A jet is then created which seems to be the cause for cavitation erosion, i.e. a form of erosion responsible for the mechanical degradation of solid materials by the action of vapor bubbles.  The eroded materials make the moving components not as effective as they should be, which leads to performance loss and important replacement costs.  Direct detection of cavitation is often impossible due to the complicated structure of the enclosure.  The numerical simulation of low Mach number cavitation flows is often the only tool available to hydraulic turbine designers.  This example shows that the accurate modeling of free surface flows can have a significant economical and industrial impact. The main objective of this research project is to develop a numerical model to study the influence of interfacial physics on the dynamics of free surfaces found in complex multiphase flows involving moving boundaries, that are found in industrial applications.  The long term goal of our research program is to provide a general analysis tool for engineers in charge of the optimization of industrial processes involving multiphase systems.

自由表面流动是工业流体力学中常见的现象。许多工业过程涉及多种流体在复杂几何形状中的流动，因此涉及分离这些流体的界面的演变。此外，通常具有随时间演变的几何形状，其有时以非常复杂的方式影响自由表面的动态。例如，水力涡轮机设计者必须考虑空化现象。当水与高速运动的转轮叶片接触时，局部地受到压降，溶解的空气成核产生气泡。2这种现象类似于沸腾。3流体流动使气泡从低压区移动到高压区。气泡可能在固体表面或靠近固体表面处剧烈内爆。然后产生射流，这似乎是造成空蚀的原因，即一种腐蚀形式，负责通过蒸汽气泡的作用使固体材料机械降解。被腐蚀的材料使运动部件不像它们应该的那样有效，由于蜗壳结构的复杂性，直接检测空化现象往往是不可能的，低马赫数空化流动的数值模拟往往是水力涡轮机研究的唯一手段这个例子表明，自由表面流的精确建模可以具有显著的经济和工业影响。本研究项目的主要目标是开发一个数值模型，研究界面物理对工业应用中涉及移动边界的复杂多相流中自由表面动力学的影响。我们研究计划的长期目标是为负责多相系统工业过程优化的工程师提供一个通用的分析工具。