High-performance numerical methods for modelling of granular flows and sediment dynamics

用于颗粒流和沉积物动力学建模的高性能数值方法

• 批准号: RGPIN-2017-06308
• 负责人: Shakibaeinia, Ahmad
• 金额: $ 2.11万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=683112
• 关键词: performance; numerical; methods; modelling; granular

Granular materials are made up of macroscopic small particles, of which sediment material is an important example. These materials are ubiquitous in nature and are the second-most manipulated material in industry (water being the first). Flow of granular materials plays a critical role in engineering, geophysical and environmental processes. It may seem confounding that in the today's world of scientific advancements, the flow of this most familiar form of matter remains largely unpredictable. This knowledge gap stems from the complex mechanical behaviour of these materials which may resemble those of solid, liquid (a non-Newtonian fluid) or even gas in different circumstances. The situation is still more complex when the granular material interacts with an ambient fluid like water. Predicting the behaviour of these so-called multiphase granular flows is critical to furthering today's limited understanding of fluvial and coastal sediment dynamics, submarine landslides, or slurry flow in tailing ponds of mining operations. ***With advances in computing power and numerical algorithms, it has become possible to numerically simulate granular flow systems, especially where physical models are restricted. Nevertheless, dealing with the complexities of multiphase granular flows is still beyond the capabilities of the many existing numerical methods. This is due to the complicated behaviour of granular material and the large deformations and fragmentations that exist at the interface of the ambient fluid and the granular material. Furthermore, to deal with the in-depth analysis of multi-scale problems, the cluster “peta-scale” computing is required. The development of a revolutionary generation of numerical techniques, the mesh-free Lagrangian (particle) methods, has provided us the first ever opportunity to overcome the granular flows complexities. These methods are known to be capable of handling the multiphase continuum with complex boundaries and interfaces. ***The proposed program, therefore, aims to (1) elaborate the theoretical foundation, describing the mechanics of multiphase granular flows, and develop novel algorithms, primarily based on the mesh-free Lagrangian methods, for numerical implementations; (2) improve the robustness and accuracy of these numerical techniques; and (3) develop massively parallel, accurate, and multi-scale algorithms, capable of PetaFLOP computation of these flow systems. The focus will be on development of models that permit accurate representation of the grain-scale motions and then harnessing the full power of modern computers to achieve scalable performance on large-scale problems. This program also aims to (4) provide new understanding of mechanisms involved in real-life multiphase granular flows, particularly for the case of sediment dynamics analysis in fluvial environments, mining tailing slurries and landslides.

颗粒材料由宏观小颗粒组成，其中沉积物材料是一个重要的例子。这些材料本质上是普遍存在的，并且是工业中第二高的操纵材料（水是第一种）。颗粒材料的流动在工程，地球物理和环境过程中起着至关重要的作用。似乎在当今的科学进步世界中，这种最熟悉的物质形式的流动在很大程度上是无法预测的。这些知识差距从这些材料的复杂机械行为中得出，这些材料可能类似于固体，液体（非牛顿液），甚至在不同情况下的气体。当颗粒材料与环境流体（如水）相互作用时，情况仍然更加复杂。预测这些所谓的多相颗粒流的行为对于进一步了解当今对河流和沿海沉积物动力学，海底滑坡或泥浆流中的有限理解至关重要。 ***随着计算能力和数值算法的进步，已经有可能单独模拟颗粒流系统，尤其是在限制物理模型的情况下。然而，处理多相颗粒流的复杂性仍然超出了许多现有数值方法的能力。这是由于颗粒材料的复杂行为以及在环境流体和颗粒物材料界面上存在的大变形和碎片。此外，要处理多尺度问题的深入分析，需要“ PETA尺度”计算。革命性一代数值技术的发展，即无网状的拉格朗日（粒子）方法，为我们提供了有史以来第一个克服颗粒状复杂性的机会。已知这些方法能够使用复杂的边界和接口处理多相连续体。 ***因此，提出的程序旨在（1）阐述理论基础，描述多相颗粒流的机制，并主要基于基于无网状的Lagrangian方法来开发新型算法，用于数值实现； （2）提高这些数值技术的鲁棒性和准确性； （3）能够对这些流量系统进行PETAFLOP计算，开发出大量平行，准确和多尺度的算法。重点将放在模型的开发上，该模型允许准确表示谷物规模的动作，然后利用现代计算机的全部力量，以在大规模问题上实现可扩展性能。该计划还旨在（4）提供对现实生活中多相颗粒流的机制的新理解，尤其是对于河流环境中的沉积物动力学分析的情况，开采尾浆和滑坡。