ITR/AP (CHE): Mutliscale Treatment of Fluid-Solid Interfaces: Development of Hybrid Monte Carlo and Finite Element Code

ITR/AP (CHE)：流固界面的多尺度处理：混合蒙特卡罗和有限元代码的开发

• 批准号: 0112929
• 负责人: Xiao Cheng Zeng
• 金额: $ 40万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0112929&HistoricalAwards=false
• 关键词: ITR; AP; CHE; Mutliscale; Treatment

0112929ZhengThis ITR/AP Small Group Award supports development of efficient and robust computational methods for simulating physical systems involving phenomena at drastically different length scales. The results will serve an important need in computer-aided design, analysis andmodeling. A classic example is a system that involves fluid-solid interfaces with complex geometries on scales ranging from molecular to macroscopic. On one hand, computational modeling approaches based on continuum approximations (e.g., finite-element and finite-difference techniques) are capable of describing mechanical responses only at wavelengths much longer than the typical distances over which the fluid density at interfaces varies appreciably. On the other hand, the whole system is far too large to be treated by a fully atomistic simulation that would encompass responses at all scales simultaneously. To address this problem a hybrid Monte Carlo-finite element scheme, in which fluid molecules at the interface are treated explicitly, while the solid is handled by continuum techniques, will be applied. A "reduced" description in which the stochastic variables consist of the positions of thefluid molecules and the nodes of the finite-element mesh covering the solid phase will be developed. The stochastic nature of Monte Carlo lends itself to an efficient parallel computing scheme, which is crucial for simulating real-world systems. A multi-disciplinary team has been assembled to undertake the three-year project, the expected outcome of which is a powerful computational scheme for analyzing the thermomechanical response of realistic fluid-solid systems in which the coupling of the molecularly heterogeneous interfaces to the macroscopic continuum plays an essential role.***

[01:12929]这个ITR/AP小组奖支持开发高效和健壮的计算方法，用于模拟涉及不同长度尺度现象的物理系统。研究结果将满足计算机辅助设计、分析和建模的重要需要。一个典型的例子是涉及从分子到宏观尺度上具有复杂几何形状的流固界面的系统。一方面，基于连续体近似的计算建模方法（例如，有限元和有限差分技术）只能在比典型距离长得多的波长上描述机械响应，而在典型距离上，界面处的流体密度变化明显。另一方面，整个系统太大了，无法用一个同时包含所有尺度反应的完全原子模拟来处理。为了解决这个问题，将采用一种混合蒙特卡罗-有限元方案，在该方案中，界面处的流体分子被明确处理，而固体则由连续体技术处理。将开发一种“简化”描述，其中随机变量由流体分子的位置和覆盖固相的有限元网格节点组成。蒙特卡罗的随机特性使其成为一种高效的并行计算方案，这对于模拟现实世界的系统至关重要。一个多学科的团队已经被召集来承担这个为期三年的项目，预期的结果是一个强大的计算方案来分析现实的流体-固体系统的热力学响应，其中分子非均质界面与宏观连续体的耦合起着至关重要的作用