SBIR Phase II: A Fast Parallel Grid-Free Method for Simulating Turbulent Incompressible Flow In/Around Time-Varying Geometries

这个小型企业创新研究(SBIR)第二阶段项目建立在为模拟时变几何内部和周围的不可压缩湍流而开发的算法的基础上。第二阶段项目计划利用开发的算法开发最先进的计算流体力学(CFD)包并将其商业化。该计算引擎基于一种先进的三维拉格朗日涡旋边界元方法的并行、自适应快速多极(FMM)实现。湍流通过使用动态Smagorinsky次网格尺度模型的大涡模拟(LES)来考虑。该方法(1)在流体域中无网格，(2)几乎无数值扩散，(3)固有的解自适应，(4)能够模拟非均匀非定常壁面边界湍流。在第二阶段，将为FMM开发更多的创新算法，以显著提高其计算速度和准确性。此外，非定常非均质流的大涡模拟模型将被实施，并使用可能引起工业关注的问题进行严格的测试。该软件是模拟和分析复杂的层流贯穿湍流现象的理想选择，这些现象包括质量流分离、非定常涡流脱落、横流中的瞬变射流和尾迹相互作用。工业界感兴趣的例子是在地面车辆或建筑物等钝体上流动，在带有旋转和移动部件的数据存储单元中流动，在内燃机中流动，以及在泵和风扇等旋转机械内和周围流动。

This Small Business Innovation Research (SBIR) Phase II project builds on algorithms developed for simulating turbulent incompressible flows in and around time-varying geometries. The Phase II project proposes to develop and commercialize a state-of-the-art computational fluid dynamics (CFD) package utilizing the algorithms developed. The computational engine is based upon an advanced parallel, adaptive fast multipole (FMM) implementation of a 3-D Lagrangian vortex-boundary element method. Turbulence is accounted for via Large Eddy Simulation (LES) using a dynamic Smagorinsky sub-grid scale model. The method is (1) grid-free in the fluid domain, (2) virtually free of numerical diffusion, (3) inherently solution-adaptive, and (4) capable of modeling inhomogeneous unsteady wall-bounded turbulent flow. During Phase II additional innovative algorithms will be developed for FMM to substantially increase it computational speed as well as accuracy. Additionally, an LES model for unsteady inhomogeneous flows will be implemented and tested rigorously using problems of potential interest to industry.The software is ideal for simulation and analysis of complex laminar-through-turbulent flow phenomena involving massive flow separation, unsteady vortex shedding, transient jets in cross-stream, and wake-body interaction. Examples of interest to industry are flow over bluff bodies such as ground vehicles or buildings, in data storage units with rotating and moving parts; in internal combustion engines; and in and around rotating machinery such as pumps and fans.