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动是湍流和多相的，并且涉及固体边界。湍流的特征在于由于不同大小和方向的涡流运动而在局部速度场中出现明显的随机波动。湍流具有很大的实际意义，因为它们的特点是强烈的混合和高传输速率。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，颗粒的运输主要是由颗粒上的流体动力学阻力。拟议的研究计划将研究湍流和多相流的特性，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面上的非湍流微流体流动。将研究四种不同的壁面流动构型。第一流动配置是湍流平面壁射流，通过将射流平行于壁引导而产生。对于具有粗糙表面的壁，粗糙度对射流的影响尚未完全了解。第二流动配置是在安装在接地平面上的有限棱镜上的流动。棱镜后产生的尾流是复杂的，包含非定常的旋涡结构。产生这些结构的确切机制尚未确定。第三种流动构型是湍流气体-颗粒流动的构型，例如在气动输送中发生的。在这种情况下，颗粒和湍流之间的相互作用是复杂的，难以纳入工程模型。最终的配置是微流体流过多孔组织支架，其促进生物组织的生长。组织表面生长和变化，以响应流动提供的营养和机械刺激。这些流动范例的研究将提供新的见解，流体如何与不同配置的固体壁相互作用。将使用新的数值和实验方法研究流动，以获得瞬时速度场，并使用先进的分析工具进行处理，以确定相关的流动结构。这些研究不仅将推进我们对流体-固体相互作用的基本理解，而且还将用于改进工程师用于预测工业和环境应用中平均流动特性的湍流和多相模型。最后，能够模拟流动的活组织，生长和变化的流动特性，将证明计算流体动力学的潜力，以提高我们对生物医学系统的理解。 ***********