Collaborative Research: Efficient Modeling of Incompressible Fluid Dynamics at Moderate Reynolds Numbers by Deconvolution LES Filters - Analysis and Applications to Hemodynamics

合作研究：通过解卷积 LES 滤波器对中等雷诺数下不可压缩流体动力学进行有效建模 - 血流动力学分析和应用

• 批准号: 1620384
• 负责人: Annalisa Quaini
• 金额: $ 17.99万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1620384&HistoricalAwards=false
• 关键词: Collaborative; Research; Efficient; Modeling; Incompressible

Computational fluid dynamics has emerged as a powerful tool to study the physiopathology of the cardiovascular system and for patient-specific Surgical Planning (SP) for cardiovascular diseases. Recently, clinical trials - the standard procedure for understanding diseases and assessing the impact of therapies and devices in the clinical practice - have been supported by a massive use of numerical simulations to improve the knowledge extracted from measured data, leading to Computer Aided Clinical Trials (CACT). For a large variety of pathologies involving the aorta - the major artery of the circulation - this requires to work with turbulent flows. While Direct Numerical Simulation in this context can be appropriate for a proof of concept, for the large number of patients involved in CACT and SP we need different numerical tools to provide the appropriate trade-off between accuracy and reliability needed by clinical applications and computational efficiency needed by tight deadlines. As CACT and SP are new emerging concepts in cardiovascular mathematics, an appropriate numerical modeling of turbulent physiological flows for clinical applications is now an unmet need that we intend to solve in this proposal.A possible way to limit the computational costs associated with Direct Numerical Simulations without sacrificing accuracy is to solve the flow average and model properly the effects of the small scales (not directly solved) at the medium and large scales (solved). We intend to investigate carefully new cutting-edge methods for disturbed flows based on Large Eddy Simulation (LES) Deconvolution filtering techniques with the ultimate goal of enabling practical use of numerical tools to improve knowledge extraction and clinical practice through CACT and SP. The main objective of this research is the development and the analysis of a robust and accurate LES based approach requiring no or minimal user's set-up for realistic incompressible flow problems with application to computational hemodynamics. We articulate the project in the following points: (a) Sensitivity analysis of key parameters involved in the method to understand their impact on the solution, leading to an automated parameter set-up through physical and numerical arguments. (b) Development and analysis of high-order in time methods, particularly for the computation of the pressure, with consequent improvement of the mass conservation properties. (c) Analysis of the impact of our LES approach on non-Dirichlet boundary conditions and the possible backflow stabilizing effects. We plan to test the method on both academic and real bioengineering problems. Finally, we plan to deliver a finite element open source library incorporating the findings of our research, available for CACT and SP.

计算流体动力学已成为研究心血管疾病的心血管系统生理病理学和患者特异性手术计划（SP）的强大工具。最近，通过大量使用数值模拟来改善从测量数据中提取的知识，从而导致计算机辅助临床试验（CACT），因此支持了临床试验 - 理解疾病和评估疗法和设备在临床实践中的影响的标准程序。对于涉及主动脉（循环的主要动脉）的多种病理，这需要与湍流作用。尽管在这种情况下的直接数值模拟可能适合于概念证明，但对于参与CACT和SP的大量患者，我们需要不同的数值工具来提供适当的权衡，以在临床应用所需的准确性和可靠性和紧缩期限所需的计算效率之间提供适当的权衡。由于CACT和SP是心血管数学中的新概念，因此现在我们打算在此建议中解决临床应用的湍流生理流的适当数值模型，这是一种未满足的需求。一种可能的方式，可以限制与直接数值模拟相关的计算成本，而无需牺牲较大的准确性和模拟较大的流量，而不是直接求解较大的范围（较大的范围）（较大的平均范围）（较大的范围）（较大的平均范围）（sill sill sill sill sill salle sall）效果（效果效应效果）效果（效果效应效果）， （已解决）。我们打算根据大型涡流模拟（LES）反卷积过滤技术仔细研究新的尖端方法，以实现实际使用数值工具，以通过CACT和SP来改善知识提取和临床实践。这项研究的主要目的是开发和分析基于LES的强大而准确的方法，需要不需要或最小的用户设置，以实现现实的不可压缩流问题，并应用于计算血液动力学。我们在以下几点中阐明该项目：（a）对方法中涉及的关键参数的敏感性分析，以了解其对解决方案的影响，从而通过物理和数值参数导致自动参数设置。 （b）时间方法中高阶的开发和分析，特别是对于压力的计算，并改善了质量保护特性。 （c）分析我们的LES方法对非迪里奇的边界条件和可能的回流稳定效应的影响。 我们计划在学术和真正的生物工程问题上测试该方法。最后，我们计划提供一个有限的元素开源库，其中包含我们的研究结果，可用于CACT和SP。