A Fast High-Order CFD for Turbulent Flow Simulation in Cardio-Devices

用于心脏设备中湍流模拟的快速高阶 CFD

基本信息

批准号：
9240015
负责人：
ADRIN GHARAKHANI
金额：
$ 43.98万
依托单位：
APPLIED SCIENTIFIC RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-05-01 至 2021-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9240015
关键词：
Acceleration Address Algorithms Benchmarking Biomedical Research Blood Cardiovascular system Code Communities Community Developments Community Practice Community of Practice Complex Computer software Controlled Study Coupling Critical Pathways Data Development Device Designs Device Safety Devices Documentation Elements Ensure Equation Evaluation Formulation Future Generations Goals Heart Valve Prosthesis Hybrids Laboratory Study Learning Liquid substance Mainstreaming Maintenance Medical Device Medical Device Designs Methods Mission Modeling Navier–Stokes equations Performance Process Pump Recommendation Research Research Design Research Infrastructure Resort Running Scheme Series Source Speed Stress Tests System Technology Time United States National Institutes of Health base blood pump cost design fluid flow interest interoperability large scale simulation migration models and simulation open source parallel computer predictive tools product development research and development shear stress simulation tool trend ventricular assist device

项目摘要

Project Summary Application of Computational Fluid Dynamics (CFD) to the flow analysis and design of complex medical devices such as prosthetic heart valves and ventricular assist devices is by now standard practice in the medical devices research and development community. However, a recent controlled study by the FDA has demonstrated the limitations of traditional CFD in predicting laminar-transitional-turbulent flows of relevance to cardiovascular devices. In particular, no statistical turbulence model used in the medical devices community benchmarked uniformly successfully against experimental data. Large Eddy Simulation (LES) was recommended in this study for future simulations. To address the recommendation of the FDA panel to use LES in future simulations we propose to develop an advanced new-generation CFD for low-Reynolds-number turbulent flows of relevance to the NIH mission, using (1) a high-order Eulerian vorticity transport method for LES in the boundary layer region, and Direct Numerical Simulation (DNS) in the immediate vicinity of the boundary; and (2) an existing meshless Lagrangian Vortex Method (LVM) for LES of the large scale flow away from the boundary layer. The velocity evaluations, which constitute roughly 80% of the computational cost, will be parallelized on multicore CPUs and multi-GPUs. The Specific Aims of the project are: Specific Aim 1: To develop a compact high-order finite volume method for laminar flow simulation via the vorticity transport equation (VTE); to accelerate the velocity evaluations on multicore CPUs and multi-GPUs; and to rigorously validate the laminar flow code using, among others, the FDA "Critical Path" problem #1 (nozzle), as well as DNS of steady and pulsatile stenotic flow. Specific Aim 2: To develop a dynamic Subgrid-Scale (SGS) model in the context of VTE and tailored for transitional flow; and to validate the high-order finite volume code for turbulent flow using, among others, the FDA "Critical Path" problem #1 (nozzle), as well as steady and pulsatile stenotic flow. Specific Aim 3: To finalize the development of the proposed hybrid code for LES of low-Reynolds-number turbulent flow by coupling the high-order Eulerian and Lagrangian vortex element solvers, accurately and stably; and to validate the final product using a series of benchmarks, including the FDA "Critical Path" problems #1 (nozzle) and #2 (pump), as well as an actual blood pump; e.g., the HeartMate II. Specific Aim 4: To implement a system for successful documentation, dissemination, and maintenance of the software, and to accommodate collaborative research; and to develop interfaces to mainstream CFD to ensure interoperability and seamless migration to the propsed technology. Long-Term Impact: At present, application of traditional CFD and statistical turbulence models is limited to the study of device performance in terms of relative trends. That is, CFD is not yet a truly predictive design and analysis tool, at least in the case of cardio-device design, which involves highly complex unsteady flow with multiple coexisting laminar, transitional, and turbulent flow regimes. The proposed high-order hybrid DNS-LES method is designed to be a predictive tool that avoids ad hoc model constants especially within the boundary layer, which is a key source of shear stress and blood damage. The proposed technology will fundamentally alter how the medical devices community will use CFD in future. The long-term significant impact of this research and technology maturation project is a CFD software that (1) is incredibly easy to learn and use, as it obviates the often tedious and error prone volumetric meshing process; (2) can be used reliably as a predictive tool thanks to the absence of turbulence models with ad hoc fudge factors, which must invariably be "calibrated" and "validated" for each new flow problem; and (3) can be run on a desktop at order-of-magnitude faster turn-around times, reducing month-long product design cycles to just days, thanks to advanced algorithms and accelerated computing on commodity multicore CPUs and multi-GPUs.

项目概要计算流体动力学（CFD）在复杂医疗流动分析与设计中的应用人工心脏瓣膜和心室辅助装置等装置目前已成为医疗领域的标准做法。医疗器械研究与开发社区。然而，FDA 最近的一项对照研究表明证明了传统 CFD 在预测与相关的层流-过渡-湍流流动方面的局限性心血管设备。特别是，医疗器械领域没有使用统计湍流模型根据实验数据成功地进行了统一基准测试。大涡模拟 (LES) 本研究中推荐用于未来的模拟。为了响应 FDA 小组关于在未来模拟中使用 LES 的建议，我们建议开发一个先进的新一代 CFD，适用于与 NIH 任务相关的低雷诺数湍流，使用 (1) 边界层区域 LES 的高阶欧拉涡量传输方法，以及 Direct 紧邻边界的数值模拟（DNS）； (2) 现有的无网格用于远离边界层的大规模流的 LES 的拉格朗日涡旋法 (LVM)。速度约占计算成本 80% 的评估将在多核 CPU 上并行化和多 GPU。该项目的具体目标是：具体目标 1：开发一种紧凑的高阶有限体积方法，用于层流模拟涡度传递方程（VTE）；加速多核 CPU 和多 GPU 的速度评估；并使用 FDA“关键路径”问题 #1 等严格验证层流代码（喷嘴），以及稳定和脉动狭窄血流的 DNS。具体目标 2：在 VTE 背景下开发动态次网格规模 (SGS) 模型，并针对过渡流；并使用以下方法验证湍流的高阶有限体积代码 FDA“关键路径”问题#1（喷嘴），以及稳定和脉动狭窄血流。具体目标 3：最终确定低雷诺数 LES 混合代码的开发通过耦合高阶欧拉和拉格朗日涡元求解器，准确且准确地计算湍流稳定；并使用一系列基准来验证最终产品，包括 FDA“关键路径” 问题#1（喷嘴）和#2（泵），以及实际的血泵；例如，HeartMate II。具体目标 4：实施一个成功记录、传播和维护软件，并适应协作研究；并开发与主流CFD的接口，以确保互操作性和无缝迁移到所提出的技术。长期影响：目前，传统CFD和统计湍流模型的应用仅限于根据相对趋势研究设备性能。也就是说，CFD 还不是真正的预测设计，分析工具，至少在有氧器械设计的情况下，其中涉及高度复杂的非定常流动多种共存的层流、过渡流和湍流流态。提出的高阶混合 DNS-LES 该方法被设计为一种预测工具，可以避免临时模型常数，尤其是在边界内层，这是剪切应力和血液损伤的关键来源。所提出的技术将从根本上改变医疗设备界未来使用 CFD 的方式。本次活动的长期重大影响研究和技术成熟项目是一款 CFD 软件，(1) 非常容易学习和使用，因为它避免了通常繁琐且容易出错的体积网格划分过程； (2) 可以可靠地用作预测由于缺乏具有临时软糖因素的湍流模型，这些工具必须始终是针对每个新的流量问题进行“校准”和“验证”； (3) 可以在桌面上以数量级运行得益于先进的技术，更快的周转时间，将长达一个月的产品设计周期缩短至几天商用多核 CPU 和多 GPU 上的算法和加速计算。