Fluid Flow and Heat and Mass Transfer in Micro-systems with Complex Physics

复杂物理微系统中的流体流动和传热传质

• 批准号: RGPIN-2017-03723
• 负责人: Mohamad, Abdulmajeed
• 金额: $ 1.82万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710500
• 关键词: Fluid; Flow; Heat; Mass; Transfer

Fluid flow and heat and mass transfers in micro devices have many engineering applications in utilizing, detecting, sensing, monitoring, and diagnosis of environmental, industrial, biological, and biomedical systems. There is a need for cheap, reliable, real-time devices to diagnose diseases, monitor environmentally harmful gases, detect biological and chemical warfare agents, etc. The focus of the current proposal will be on investigating the physics of flow and droplets in microfluidic systems. Mathematical models and simulation tools need to be developed. The newly created knowledge leads to better understanding the operation of droplet micro devices, improve the design of novel diagnostic devices, such as flow focusing and digital droplet devices, and in developing a new technology. In the long term, it is intended to expand our results for developing industrial and environmental monitoring devices. Microfluidic and Nanofluidic devices have emerged as potent instruments for diagnosis of diseases. Extensive research has been done on different types of microfluidic devices for a wide spectrum of applications with different geometrical configurations. However, most of the works are done by a trial and error to optimize the operation in those devices. The flow is laminar, where the mixing process is mainly controlled by a slow diffusion mechanism. The fluid flow is also in two or multi-phases with droplets. The mixing processes are usually carried out by an applied external force, such as electric, thermal, magnetic, or acoustic. The topic of two or multi-phase and/or multicomponent flows is a very challenging task, computationally. Most analysis has been based on empirical correlations and non-exact science. Moreover, the fluid-structure interaction on micro- and nano-scales is not fully understood. The problem becomes more challenging with extra physics, such as electrical force, Joule heating, unsteady flows, etc. Hence, there is a need to understand and develop solid underlying physics of the problem and develop a mathematical model for simulations of those devices. The simulation results help us to understand the physics and the effects of the controlling parameters. Also, simulation is cost effective in the optimization process of such devices. Conventional CFD methods have many limitations when it comes to dealing with multi-phase flows. On the other hand, the Lattice Boltzmann method (LBM) is a very powerful alternative method compared with the conventional methods to solve fluid dynamics problems. In LBM, it is relatively easy to integrate thermodynamics with transport equations. Besides, it enjoys simple coding and can be easily used with parallel processor computers. The outcome of the research will help in developing novel, reliable and real-time, droplet-based microfluidic devices for many applications. The outcomes will contribute to the Canadian economy.

微器件中的流体流动和传热传质在环境、工业、生物和生物医学系统的利用、检测、传感、监测和诊断等方面有着广泛的工程应用。需要廉价、可靠、实时的设备来诊断疾病、监测环境有害气体、检测生物和化学战剂等。当前提议的重点将放在研究微流控系统中的流动和液滴的物理上。需要开发数学模型和仿真工具。新创造的知识有助于更好地了解液滴微设备的操作，改进新型诊断设备的设计，如流动聚焦和数字液滴设备，以及开发新技术。从长远来看，它旨在扩大我们在开发工业和环境监测设备方面的成果。 微流控和纳米流控装置已成为诊断疾病的有力工具。人们对不同类型的微流控器件进行了广泛的研究，这些器件具有不同的几何结构，应用范围很广。然而，大多数工作都是通过反复试验来优化这些设备的操作。流动为层流，混合过程主要受慢扩散机制控制。流体流动也是带有液滴的两相或多相流动。混合过程通常由施加的外力执行，如电、热、磁或声。从计算上讲，两相或多相和/或多组分流动的主题是一个非常具有挑战性的任务。大多数分析都是基于经验相关性和非精确科学。此外，在微米和纳米尺度上的流固相互作用还没有被完全理解。有了额外的物理因素，如电动力、焦耳加热、非定常流动等，这个问题就变得更具挑战性。因此，有必要了解和发展问题的坚实基础物理，并开发一个用于模拟这些设备的数学模型。 仿真结果有助于我们了解控制参数的物理意义和影响。此外，在这种设备的优化过程中，模拟是具有成本效益的。传统的CFD方法在处理多相流时有很多局限性。另一方面，与传统方法相比，格子Boltzmann方法(LBM)是求解流体力学问题的一种非常有效的替代方法。在LBM中，热力学和输运方程的结合相对容易。此外，它具有编码简单、易于与并行处理机配合使用等优点。研究结果将有助于开发新型的、可靠的、实时的、基于液滴的微流控器件。这些结果将为加拿大经济做出贡献。