Strongly Coupled Fluid-Structure Interaction with Application to Blood Flow in Deformable Arteries

本项目的研究目标是通过开发具有最小二乘公式和算法的谱/惠普有限元来克服当前使用的计算技术的不足。流体和固体的物理相互作用在工程学的各个分支中都具有实际意义。例如，气动结构的颤振、爆炸引起的结构变形、海底管道和立管的涡激振动、充气坝、降落伞动力学以及通过动脉的血液流动。由于流体和固体是由不同的方程组描述的，所以它们是独立求解的，从流体流动方程计算的牵引力用作对结构的作用力。牵引力引起的结构几何变化反过来又会影响流动特性。当涉及高速流动和/或几何复杂结构时，这种双向耦合可能是重要的。本研究采用了单一的计算框架，从而提高了流体和固体的物理耦合的兼容性和准确性。流体和固体之间的耦合是使用隐式强耦合分区过程来实施的。通过可变形动脉的血液流动将被用作基准问题。开发的计算框架具有改变诊断能力的潜力，例如，血液相关疾病的发起和传播，以及航空航天结构设计。这项研究还将修改一些结构力学和计算方法的课程，包括研究流固相互作用问题的方法，并使学生能够在设计涉及流固耦合的系统时找到准确的社会挑战的解决方案。

The research objective of this project is to overcome the deficiencies of the currently used computational technologies by developing spectral/hp finite elements with least-squares formulation and algorithms. The physical interaction of fluids and solids is of practical significance in various branches of engineering. Examples include flutter of aerodynamic structures, structural deformation due to explosions, vortex induced vibrations of sub-sea pipelines and risers, inflatable dams, parachute dynamics, and blood flow through arteries. Since fluids and solids are described by different sets of equations, they are solved independently and the tractions calculated from the fluid flow equations is used as applied force on the structure. Geometric changes of the structure due to the tractions in turn influences the flow characteristics. This two-way coupling can be significant when high-speed flows and/or geometrically complex structures are involved. The present study employs a single computational framework that allows for enhanced compatibility and accuracy in the physical coupling of the fluid and solid. The coupling between the fluid and solid is enforced using implicit strongly coupled partitioned procedures. Blood flow through deformable arteries will be used as a benchmark problem.The developed computational framework has the potential to transform, for example, diagnostic capabilities for the initiation and propagation of blood-related diseases, and aerospace structures design. The research will also revamp some of the courses in structural mechanics and computational methods to include approaches to study fluid-solid interaction problems and enable students to find accurate solutions to societal challenges in designing systems involving fluid-solid couplings.