Two-phase flow numerical model development based on experimental characterization.

基于实验表征的两相流数值模型开发。

• 批准号: RGPIN-2020-06629
• 负责人: Beguin, Cedric
• 金额: $ 2.7万
• 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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754401
• 关键词: Two; phase; flow; numerical; model

Two-phase flow numerical model development based on experimental characterization The proposed research program is built to design innovative experiments and develop a theoretical framework for two-phase flows. For industrial applications, the Navier-Stokes equations governing the flows are averaged. This averaging process produces a loss of information on small-scale phenomena. Consequently, modeling these phenomena is required to adequately close numerical models. Our constant concern will be to create experiments to understand and model these small-scale phenomena as the guideline of my research objectives. New developed models will then be implemented in numerical codes based on the averaged Navier-Stokes equations and validated by comparison with large-scale phenomenon experiments. This specific philosophy creates a synergy between numerical and experimental approaches often conducted separately. Three specific objectives support this research vision: a) Model two-phase flow-structure interactions: A first project will study the bubble formation occuring during resin injection for composite manufacturing due to the double scale of the fibre structure. A second project will study the two-phase boundary layer characteristics. Formulating a law of the wall from empirical correlations for two-phase flows would allow numerical predictions at a reasonable cost for complex geometries such as those encountered in the industry and of much better quality than current predictions. b) Determine Particle-particle interactions: A first project will study the phenomenon of coalescence between bubbles inside a two-phase flow, by observing a few bubbles coalescing. The coalescence is part of the balance that governs the bubble sizes and therefore ultimately their trajectories. A second project will measure the turbulence induced by bubbles thanks to innovative technical measurement tools. c) Construct correlation for forces on submerged particles: A first project will numerically assess a bubble rising close to a wall. A second project will study the lift forces of a few particles. If correlations of the force coefficient for isolated particles are relatively well known, their corresponding correlation still requires improvements. A cloud of bubbles placed between a moving bell and a fixed wall will be monitored. A third project will study the drag of a bubble by observing the wake of a rising bubble thanks to 3D PIV. Thus, the research we propose will focus on fundamental experiments to construct an accurate and consistent formulation for dispersed flow simulations. This innovative research will lead to the development of better computational models to shed insight into a variety of two-phase flow problems that affect the welfare of the Canadian population and the competitiveness of the Canadian industry. The lack of reliable two-phase flow numerical procedures prevents breakthrough on the numerous industrial processes using two-phase flow.

基于实验表征的两相流数值模型开发所提出的研究计划旨在设计创新实验并开发两相流的理论框架。对于工业应用，控制流量的纳维-斯托克斯方程被平均。这种平均过程会导致小规模现象的信息丢失。因此，需要对这些现象进行建模以充分接近数值模型。我们始终关注的是创建实验来理解和模拟这些小规模现象，作为我研究目标的指导方针。然后，新开发的模型将在基于平均纳维-斯托克斯方程的数值代码中实施，并通过与大规模现象实验的比较进行验证。这种特定的理念在通常单独进行的数值方法和实验方法之间创造了协同作用。三个具体目标支持这一研究愿景： a) 模拟两相流-结构相互作用：第一个项目将研究复合材料制造的树脂注射过程中由于纤维结构的双尺度而发生的气泡形成。 第二个项目将研究两相边界层特征。根据两相流的经验相关性制定墙体定律将允许以合理的成本对复杂的几何形状（例如工业中遇到的几何形状）进行数值预测，并且比当前的预测质量要好得多。 b) 确定粒子与粒子之间的相互作用：第一个项目将通过观察一些气泡的聚结来研究两相流内气泡之间的聚结现象。合并是控制气泡大小并最终控制其轨迹的平衡的一部分。第二个项目将利用创新的技术测量工具来测量气泡引起的湍流。 c) 构建水下粒子上的力的相关性：第一个项目将对靠近墙壁升起的气泡进行数值评估。第二个项目将研究一些粒子的升力。如果孤立粒子的力系数的相关性相对众所周知，那么它们相应的相关性仍然需要改进。放置在移动钟和固定墙之间的气泡云将被监测。第三个项目将通过 3D PIV 观察上升气泡的尾迹来研究气泡的阻力。因此，我们建议的研究将侧重于基础实验，为分散流模拟构建准确且一致的公式。这项创新研究将导致更好的计算模型的开发，以深入了解影响加拿大人口福利和加拿大工业竞争力的各种两相流问题。缺乏可靠的两相流数值程序阻碍了使用两相流的众多工业过程的突破。