论文标题
FDA喷嘴基准的功效和晶格Boltzmann方法在过渡方案中分析生物医学流的功效
Efficacy of the FDA nozzle benchmark and the lattice Boltzmann method for the analysis of biomedical flows in transitional regime
论文作者
论文摘要
尽管处于适度的雷诺数字，但流过医疗设备以及解剖血管中的流动可能表现出过渡性甚至湍流特征。为了验证用于生物医学流量计算的数值方法和代码，美国食品药品监督管理局（FDA）建立了实验基准，该基准是一种逐渐收缩和突然膨胀的管道，代表喷嘴。公开发布的各种雷诺数字的实验结果范围为500至6500。 FDA喷嘴中流动流的以前和最近的计算研究发现了各种CFD方法的局限性，甚至有些甚至质疑了基准本身的充分性。该沟通报告了基于晶格Boltzmann方法（LBM）的直接数值模拟（DNS）方法的结果应用于FDA喷嘴基准，用于Reynolds数字2000和3500的过渡案例。目标是评估简单的零件是否可以预测实验结果，而无需使用复杂模型或同步型的实验结果。通过各种空间和时间分辨率进行LBM计算，在4400万至28亿个晶格细胞中进行了32台CPU核心，分别在32个CPU核心上进行台式机，以探索和量化Miniscule Flow细节并量化Kolmogorov量表的300'000个核心。 LBM模拟在Reynolds数字2000上的湍流过渡，例如FDA的实验以及在JET分解位置的可接受一致性，平均速度，剪切应力和压力都在两个雷诺数中都发现。
Flows through medical devices as well as in anatomical vessels despite being at moderate Reynolds number may exhibit transitional or even turbulent character. In order to validate numerical methods and codes used for biomedical flow computations, the U.S. food and drug administration (FDA) established an experimental benchmark, which was a pipe with gradual contraction and sudden expansion representing a nozzle. The experimental results for various Reynolds numbers ranging from 500 to 6500 were publicly released. Previous and recent computational investigations of flow in the FDA nozzle found limitations in various CFD approaches and some even questioned the adequacy of the benchmark itself. This communication reports the results of a lattice Boltzmann method (LBM) based direct numerical simulation (DNS) approach applied to the FDA nozzle benchmark for transitional cases of Reynolds numbers 2000 and 3500. The goal is to evaluate if a simple off the shelf LBM would predict the experimental results without the use of complex models or synthetic turbulence at the inflow. LBM computations with various spatial and temporal resolutions are performed - in the extremities of 44 million to 2.8 billion lattice cells - conducted respectively on 32 CPU cores of a desktop to more than 300'000 cores of a modern supercomputer to explore and characterize miniscule flow details and quantify Kolmogorov scales. The LBM simulations transition to turbulence at a Reynolds number 2000 like the FDA's experiments and acceptable agreement in jet breakdown locations, average velocity, shear stress and pressure is found for both the Reynolds numbers.
