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

• 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
• 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

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.

项目摘要 计算流体力学（CFD）在复杂医疗设备流动分析与设计中的应用 诸如人工心脏瓣膜和心室辅助装置的装置现在是本领域的标准实践。 医疗器械研究和开发社区。然而，FDA最近的一项对照研究表明， 证明了传统计算流体力学在预测层流过渡湍流方面的局限性， 心血管设备特别是，没有统计湍流模型用于医疗器械界 一致成功地对实验数据进行了基准测试。大涡模拟（LES） 建议在本研究中用于未来的模拟。 为了解决FDA专家组在未来模拟中使用LES的建议，我们建议开发一个 与NIH使命相关的低雷诺数湍流的先进新一代CFD， 采用（1）高阶欧拉涡度输运方法计算边界层区域的大涡模拟， 边界附近的数值模拟（DNS）;（2）现有的无网格 拉格朗日涡方法（LVM）用于大尺度远离边界层流动的大涡模拟。速度 计算约占计算成本的80%，将在多核CPU上并行化 多GPU。该项目的具体目标是： 具体目标1：开发一种用于层流模拟的紧凑型高阶有限体积方法， Vorticity Transport Equation（VTE）;加速多核CPU和多GPU上的速度评估; 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流的DNS。 具体目标2：在VTE背景下开发动态亚网格尺度（SGS）模型， 过渡流;并验证湍流的高阶有限体积代码，其中使用 FDA“关键路径”问题#1（喷嘴），以及稳定和脉动狭窄流。 具体目标3：完成低雷诺数大涡模拟混合代码的开发 湍流耦合高阶欧拉和拉格朗日涡元求解器，准确， 稳定;并使用一系列基准验证最终产品，包括FDA的“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：建立一个系统，成功地记录、传播和维护 软件，并适应合作研究;并开发主流CFD的接口，以确保 互操作性和无缝迁移到建议的技术。 长期影响：目前，传统CFD和统计湍流模型的应用仅限于 根据相对趋势研究器械性能。也就是说，CFD还不是真正的预测设计， 分析工具，至少在心脏设备设计的情况下，涉及高度复杂的非定常流， 多种共存的层流、过渡流和湍流状态。提出的高阶混合DNS-LES 方法被设计成一种预测工具，它避免了特别是在边界内的特设模型常数 层，这是剪切应力和血液损伤的关键来源。这项技术将从根本上 改变医疗器械界未来使用CFD的方式。其长期重大影响 研究和技术成熟项目是一个CFD软件，（1）非常容易学习和使用，因为它 避免了通常繁琐和容易出错的体积网格化过程;（2）可以可靠地用作预测 由于缺少带有特殊模糊因子的湍流模型， “校准”和“验证”为每个新的流量问题;和（3）可以在桌面上运行的数量级 更快的周转时间，将长达一个月的产品设计周期缩短到几天，这要归功于先进的 在商用多核CPU和多GPU上实现算法和加速计算。