SBIR Phase II: Large Eddy Simulations (LES) of Gas-Particle Flows

这一小型企业创新研究(SBIR)第二阶段项目将进一步开发、验证和演示用于预测气固两相流动现象的大涡模拟(LES)。第一阶段的研究已经清楚地证明了使用商业CFD程序在简单几何形状的流动中进行气固两相大涡模拟的可行性。对各向同性和槽道湍流中颗粒的扩散、沉积和团聚进行了较好的预测。第二阶段的研究将完善第一阶段开发的模型和技术，并将其扩展到在实际几何形状中模拟更复杂的流动。第二阶段的工作将侧重于以下主要领域：非结构化和混合单元(自适应笛卡尔)网格(由快速和准确模拟的需要驱动)；调整和实施高级亚网格尺度模型和在这些替代网格拓扑中的颗粒传输；实施用于(A)流体亚网格尺度(SGS)速度(B)沉积和(C)团聚的增强粒子亚网格模型；在通道、自由剪切和混合层流动中进行广泛和系统的验证；使用实际污染物传输模拟进行技术演示。一支由经验丰富的研究人员和对这种能力感兴趣的终端用户(Aerodyne Research、PLG、Dura PharmPharmticals)组成的团队已经组建完毕。第二阶段工作的最终产品将是用于气固两相流动的集成大涡模拟系统(具有先进的网格、解算器和可视化软件)。如果不详细考虑流动和颗粒运动之间复杂且通常高度非线性的相互作用，通常不能很好地理解气体-颗粒过程。开发的集成大涡模拟系统将促进对复杂几何形状中稀薄颗粒湍流流动的更好的基本理解。它将使各种领域的工程设计得到改进，如空气污染控制和化学/生物恐怖主义计划，以及化学/制药/半导体加工。在第二阶段结束时开发的产品将把迄今为止仅供院士使用的复杂物理模拟器交到训练有素的工业工程师手中，使其能够更好地理解和改进相关过程。

This Small Business Innovation Research (SBIR) Phase II project will further develop, validate and demonstrate Large Eddy Simulations (LES) for the prediction of gas-particle flow phenomena. The Phase I study has clearly demonstrated the feasibility of using a commercial CFD code to perform Gas-Particle Large Eddy Simulations in flows with simple geometry. Good predictions of particulate dispersion, deposition and agglomeration in isotropic and channel turbulent flows have been obtained. The Phase II study will refine the models and techniques developed in Phase I and extend them to simulate more complex flows, in practical geometries. The Phase II work will be focused on the following main areas: unstructured and mixed element (adaptive cartesian) grids (driven by the need for fast and accurate simulations; adaptation and implementation of advanced sub-grid scale models and particle transport in these alternative grid topologies; implementation of enhanced particle sub-grid scale models for (a) fluid sub-grid scale (SGS) velocity (b) deposition and (c) agglomeration; extensive and systematic validation in channel, free shear and mixing layer flows; technology demonstration using a practical contaminant transport simulation. A team of experienced investigators and strongly interested end-users of this capability (Aerodyne Research, PLG, Dura Pharmaceuticals) has been assembled. The end-product of the Phase II effort will be an Integrated Large Eddy Simulation System for gas-particle flows (featuring advanced gridding, solver and visualization software). Gas-particle processes cannot usually be well-understood without a detailed consideration of the complex and usually highly nonlinear interaction between the flow and the motion of the particles. The developed Integrated Large Eddy Simulation System will foster a better fundamental understanding of dilute particulate turbulent flows in complex geometries. It will enable improved engineering design in a variety of fields such as air pollution control and chemical/bio-terrorism programs to chemical/pharmaceutical/semiconductor processing. The product developed at the end of Phase II will put a sophisticated physics simulator heretofor only avaialbe with academicians and that too in simple flow situations, in the hands of a trained industrial engineer enabling him to better understand and improve the processes of concern.