CAREER: Consistent Continuum Formulation and Robust Numerical Modeling of Non-Isothermal Phase Changing Multiphase Flows

职业：非等温相变多相流的一致连续体公式和鲁棒数值模拟

• 批准号: 2234387
• 负责人: Amneet Pal Bhalla
• 金额: $ 52.06万
• 依托单位: San Diego State University Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2028-02-29
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2234387&HistoricalAwards=false
• 关键词: CAREER; Consistent; Continuum; Formulation; Robust

Numerical modeling of phase change problems is crucial to understanding many natural and engineering processes. For example, ice formation and additive manufacturing. A major challenge arises from the coupling of heat transfer and fluid dynamics equations. Water, polymers, and metals all exhibit changes during processes like melting or evaporation that must also be considered in the model. Although several advances have been made in modeling some phase change processes, the modeling of three phase gas-liquid-solid flows with simultaneous melting, solidification, evaporation, and condensation (MSEC) remains an unsolved problem. In this project, the researchers will formulate a robust numerical scheme for simulating three-phase gas-liquid-solid flows that can undergo simultaneous MSEC and volume shrinkage/expansion. This method would permit realistic simulations and optimization of emerging manufacturing technologies like additive manufacturing and thin film deposition, where all four modes of phase change occur simultaneously. Additionally, the project provides significant educational activities, including training students in scientific and high-performance computing, outreach activities, and sharing of research codes through open-source software.This project will develop governing equations for multi-phase gas-liquid-solid flows with phase change that are consistent both at the continuous and discrete levels. The project focuses on ensuring the stability of the numerical scheme when all four modes of phase change are present. It is especially critical for flows with significant volumetric changes and with high-density contrast. Analytical and experimental validation are also part of this project. To validate that the numerical scheme captures the density/volume change during phase transition, a novel analytical model is proposed. The framework will be further validated with experimental data from the National Institute of Standards and Technology (NIST) on metal solidification and evaporation. This project will result in an experimentally validated framework that will assist in simulating and understanding metal additive manufacturing processes such as selective laser melting and powder bed fusion. Advanced computer simulations will allow the manufacturing industry to optimize process parameters, such as laser scan speed and gas flow rates, to ensure high-quality and defect-free printed parts. The numerical methods of this project will be made open source with user-friendly documentation via IBAMR software. In order to increase student participation in computing, the researcher will offer: (1) a new project-based course on Applied Scientific Computing; (2) organize summer workshops on high-performance computing (HPC) in partnership with the San Diego-based HPC industry; and (3) work with SDSU programs to recruit students from local high schools and community colleges to provide summer internship opportunities.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

相变问题的数值建模对于理解许多自然和工程过程至关重要。例如，冰的形成和增材制造。传热和流体动力学方程的耦合产生了一个主要挑战。水、聚合物和金属在熔化或蒸发等过程中都会表现出变化，模型中也必须考虑这些变化。尽管在模拟某些相变过程方面已经取得了一些进展，但同时熔化、凝固、蒸发和冷凝 (MSEC) 的三相气-液-固流的建模仍然是一个未解决的问题。在这个项目中，研究人员将制定一个强大的数值方案来模拟三相气-液-固流，这些流可以同时进行 MSEC 和体积收缩/膨胀。这种方法将允许对新兴制造技术（如增材制造和薄膜沉积）进行真实的模拟和优化，其中所有四种相变模式同时发生。此外，该项目还提供重要的教育活动，包括对学生进行科学和高性能计算方面的培训、外展活动以及通过开源软件共享研究代码。该项目将开发多相气-液-固流的控制方程相变在连续和离散水平上都是一致的。该项目的重点是在所有四种相变模式都存在时确保数值方案的稳定性。这对于具有显着体积变化和高密度对比度的流动尤其重要。分析和实验验证也是该项目的一部分。为了验证数值方案捕获相变期间的密度/体积变化，提出了一种新的分析模型。该框架将利用美国国家标准与技术研究院 (NIST) 关于金属凝固和蒸发的实验数据得到进一步验证。该项目将产生一个经过实验验证的框架，该框架将有助于模拟和理解金属增材制造工艺，例如选择性激光熔化和粉末床熔合。先进的计算机模拟将使制造业能够优化工艺参数，例如激光扫描速度和气体流速，以确保高质量和无缺陷的打印零件。该项目的数值方法将通过 IBAMR 软件开源，并提供用户友好的文档。为了增加学生对计算的参与，研究人员将提供：（1）一门新的基于项目的应用科学计算课程； (2) 与圣地亚哥 HPC 行业合作组织高性能计算 (HPC) 夏季研讨会； (3) 与 SDSU 项目合作，从当地高中和社区学院招收学生，提供暑期实习机会。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，认为值得支持。

项目成果

Sparse Approximate Multifrontal Factorization with Composite Compression Methods

复合压缩方法的稀疏近似多锋分解

• DOI: 10.1145/3611662
• 发表时间: 2023
• 期刊: ACM Transactions on Mathematical Software
• 影响因子: 2.7
• 作者: Claus, Lisa;Ghysels, Pieter;Liu, Yang;Nhan, Thái Anh;Thirumalaisamy, Ramakrishnan;Bhalla, Amneet Pal;Li, Sherry
• 通讯作者: Li, Sherry

An effective preconditioning strategy for volume penalized incompressible/low Mach multiphase flow solvers

• DOI: 10.1016/j.jcp.2023.112325
• 发表时间: 2023-06
• 期刊: J. Comput. Phys.
• 作者: R. Thirumalaisamy;K. Khedkar;P. Ghysels;A. Bhalla

A low Mach enthalpy method to model non-isothermal gas–liquid–solid flows with melting and solidification

低马赫焓法模拟非等温气体-液体-固体流动的熔化和凝固

• DOI: 10.1016/j.ijmultiphaseflow.2023.104605
• 发表时间: 2023
• 期刊: International Journal of Multiphase Flow
• 影响因子: 3.8
• 作者: Thirumalaisamy, Ramakrishnan;Bhalla, Amneet Pal
• 通讯作者: Bhalla, Amneet Pal