Advanced modeling of flows with turbulence, multiple phases and complex surfaces

湍流、多相和复杂表面流动的高级建模

• 批准号: RGPIN-2016-05103
• 负责人: Bergstrom, Donald
• 金额: $ 1.89万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=681352
• 关键词: Advanced; modeling; flows; turbulence; multiple

Many industrial and environmental flows of interest to engineers are turbulent and multiphase, and involve a solid boundary. A turbulent flow is characterized by apparently random fluctuations in the local velocity field due to eddy motions of different size and orientation. Turbulent flows are of great practical importance, since they are characterized by intense mixing and high transport rates. One important multiphase flow is the flow of a fluid containing solid particles. In this case, the particle transport is dominated by the hydrodynamic drag forces on the particles. The proposed research program will investigate the characteristics of turbulent and multiphase flows, with a focus on the fluid interaction with the solid surfaces. It will also study non-turbulent, micro-fluidic flows over complex walls associated with living tissues.******Four different wall flow configurations will be studied. The first flow configuration is a turbulent plane wall jet, created by directing a jet parallel to a wall. For walls with a rough surface, the effect of the roughness on the jet is not yet fully understood. The second flow configuration is flow over a finite prism mounted on a ground plane. The wake created behind the prism is complex and contains unsteady vortical structures. The exact mechanism for the generation of these structures has not yet been determined. The third flow configuration is that of turbulent gas-particle flow, such as occurs in pneumatic transport. In this case, the interaction between the particles and the turbulence is complex and difficult to incorporate in engineering models. The final configuration is micro-fluidic flow through a porous tissue scaffold which facilitates the growth of biological tissue. The tissue surface grows and changes in response to the nutrients and mechanical stimulation supplied by the flow.******The study of these flow paradigms will provide new insight as to how a fluid interacts with solid walls of different configurations. The flows will be studied using novel numerical and experimental methods to obtain the instantaneous velocity fields, which will be processed using advanced analysis tools to identify the pertinent flow structures. These studies will not only advance our fundamental understanding of fluid-solid interactions, but will also be used to improve the turbulence and multiphase models used by engineers to predict mean flow properties in industrial and environmental applications. Finally, the ability to simulate flow over a living tissue, which grows and changes in response to the flow characteristics, will demonstrate the potential of computational fluid dynamics to enhance our understanding of biomedical systems. ***********

工程师感兴趣的许多工业和环境流都是动荡和多相，涉及固体边界。湍流的特征是由于不同大小和方向的涡流而导致局部速度场中的随机波动。动荡的流动非常重要，因为它们的特征是混合和高运输速率。一种重要的多相流是含有固体颗粒的流体的流动。在这种情况下，粒子传输由颗粒上的流体动力阻力支配。提出的研究计划将研究湍流和多相流的特征，重点是流体与固体表面的相互作用。它还将研究与活组织相关的复杂壁上的非扰动的微富流向。******将研究四种不同的壁流构型。第一个流程配置是一种湍流的平面壁射流，它是通过引导平行于墙壁的射流而创建的。对于表面粗糙的墙壁，粗糙度对喷气机的影响尚未完全理解。第二个流程配置是在安装在接地平面上的有限棱镜上流动的。棱镜背后创建的尾流很复杂，并且包含不稳定的涡流结构。这些结构生成的确切机制尚未确定。第三个流量构型是湍流气体流量，例如气动转运中发生。在这种情况下，颗粒与湍流之间的相互作用很复杂且难以合并到工程模型中。最终的构型是通过多孔组织支架的微富集流，从而促进了生物组织的生长。组织表面的生长和随着流量提供的营养和机械刺激的响应而变化。******对这些流量范式的研究将提供有关流体如何与不同构型的固体壁相互作用的新见解。将使用新型的数值和实验方法研究流量以获得瞬时速度场，该方法将使用先进的分析工具来对其进行处理，以识别相关的流量结构。这些研究不仅将提高我们对流体固定相互作用的基本理解，而且还将用于改善工程师使用的湍流和多相模型，以预测工业和环境应用中的平均流量。最后，模拟流过流动组织的流动的能力（随着流动特征的响应而变化并变化）将证明计算流体动力学的潜力以增强我们对生物医学系统的理解。 ***********