Lattice Boltzmann Method for Real Time Simulations of Complex Physics of Blood Flows

血液由红细胞、白色细胞和血小板组成，此外还有其他成分，如营养素、激素，甚至病毒。这些不混溶的颗粒是可变形的，并且漂浮在等离子体中，等离子体在弹性通道中流动，这增加了建模的复杂性。了解血液流动的模式可能有助于了解心脏病、高血压和动脉凝血。此外，了解狭窄通道中的流动模式对于开发更好的设计以减少狭窄的影响是重要的。了解药物输送的效果及其对血液物理性质（如粘度和密度）的影响至关重要。研究这种复杂的流动物理学的一种方法是通过建模（CFD）。近年来，人们对将格子玻尔兹曼方法（LBM）应用于离散力学的兴趣越来越大，它已成为解决此类物理问题的一种强有力的技术。LBM易于编码，并且具有允许包含多物理场来解决手头问题的灵活性，增加了一系列进一步的可能应用。然而，该方法相对较新，还有很大的扩展空间，特别是在多物理领域。该提案的主要目标是：了解可变形和非光滑血管中复杂血流的物理特性，以模拟真实的血流。开发和解决更现实的血液流动模型，在特定的和多相流，在一般情况下，这将提高我们对血液流动阻塞的物理学，药物输送过程和与之相关的健康问题的理解。数学模型将使用基于离散方法的统一方法，LBM为这样的系统开发。所开发的模型将被应用于特定的问题（血液流动，生物细胞中的流动）。此外，该模型将利用LBM的本地特性，利用多处理器计算机与图形卡，以加快真实的时间模拟。此外，实验室规模的实验将进行验证开发的模型。实验数据和流动可视化将有助于加强我们对所考虑的复杂现象的物理学的理解。该项目将培训几名研究生，并为他们解决多学科，具有挑战性的工业/生物问题做好准备。

Blood consists of red and white blood cells and platelets in addition to other constituents such as nutrients, hormones, and even viruses. These immiscible particles are deformable and float in a plasma which flows in elastic channels which increases the complexity for modeling. Understanding the pattern of blood flow may shed light on heart disease, hypertension, and artery clotting. Also, understanding the flow pattern in channels with stenosis is important for developing better devises to reduce the effect of stenosis. It is vital to understand the effect of drug delivery and its effect on the blood’s physical properties, such as viscosity and density. One approach to study such complex flow physics is by modeling (CFD). Recently, there has been a growing interest in applying the Lattice Boltzmann method (LBM) to discrete mechanics which has emerged as a powerful technique to tackle such physical problems. The LBM is easy to code, and enjoys the flexibility of allowing the inclusion of multi-physics to solve the problems at hand, adding an array of further possible applications. However, the method is relatively new, much room remains for expanding it, especially in the realm of multi-physics. The main objectives of this proposal are: to understand the physics of complex blood flows in deformable and non-smooth vessels to mimic real blood flow. To develop and solve more realistic models for blood flow, in specific and multiphase flows, in general, which will enhance our understanding of the physics of blood flow blockage, drug delivery processes and health problems associated with it. Mathematical models will be developed for such systems using a unified approach based on discrete method, the LBM. The developed models will be applied to specific problems (blood flow, flows in biological cells). Also, the model will take advantage of the local nature of LBM to utilize multi-processor computers with graphic cards to speed real time simulations. Moreover, lab scale experiments will be performed to validate the developed models. The experimental data and flow visualizations will help to reinforce our understanding of the physics of the complex phenomena under consideration. The project will train several graduate students and prepare them for solving multi-disciplinary, challenging industrial/biological problems.