Laboratory of Fluid Dynamics and Technical Flows, University of Magdeburg "Otto von Guericke", Magdeburg D-39106, Germany.
Univ. Gustave Eiffel, Inria, Cosys/SII, I4S, Bouguenais F-44344, France.
Comput Methods Programs Biomed. 2022 Jun;221:106863. doi: 10.1016/j.cmpb.2022.106863. Epub 2022 May 10.
Contrary to flows in small intracranial vessels, many blood flow configurations such as those found in aortic vessels and aneurysms involve larger Reynolds numbers and, therefore, transitional or turbulent conditions. Dealing with such systems require both robust and efficient numerical methods.
We assess here the performance of a lattice Boltzmann solver with full Hermite expansion of the equilibrium and central Hermite moments collision operator at higher Reynolds numbers, especially for under-resolved simulations. To that end the food and drug administration's benchmark nozzle is considered at three different Reynolds numbers covering all regimes: (1) laminar at a Reynolds number of 500, (2) transitional at a Reynolds number of 3500, and (3) low-level turbulence at a Reynolds number of 6500.
The lattice Boltzmann results are compared with previously published inter-laboratory experimental data obtained by particle image velocimetry. Our results show good agreement with the experimental measurements throughout the nozzle, demonstrating the good performance of the solver even in under-resolved simulations.
In this manner, fast but sufficiently accurate numerical predictions can be achieved for flow configurations of practical interest regarding medical applications.
与小颅内血管中的流动不同，许多血流形态，如主动脉血管和动脉瘤中的血流形态，涉及更大的雷诺数，因此存在过渡或湍流条件。处理此类系统需要强大且高效的数值方法。
我们在此评估在更高雷诺数下采用平衡全 Hermite 展开和中心 Hermite 矩碰撞算子的格子 Boltzmann 求解器的性能，尤其是在欠解析模拟中。为此，考虑了食品和药物管理局的基准喷嘴，涵盖了所有三种不同的雷诺数：（1）雷诺数为 500 的层流，（2）雷诺数为 3500 的过渡流，以及（3）雷诺数为 6500 的低水平湍流。
格子 Boltzmann 结果与先前通过粒子图像测速法获得的跨实验室实验数据进行了比较。我们的结果在整个喷嘴中与实验测量值吻合良好，即使在欠解析模拟中，也证明了求解器的良好性能。
通过这种方式，可以针对医学应用中具有实际意义的流动形态实现快速但足够精确的数值预测。
