Massively Parallel Simulation of the Melt Pool Area during Laser Beam Welding using the Lattice Boltzmann Method

使用格子玻尔兹曼方法大规模并行模拟激光束焊接过程中的熔池区域

• 批准号: 457105421
• 金额: --
• 依托单位: Lehrstuhl für Informatik 10: Systemsimulation
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/457105421?language=en
• 关键词: Massively; Parallel; Simulation; Melt; Pool

As a flexible and contact-free joining technology, laser beam welding has increasingly gained importance. Processing of alloys with large melting range poses a challenge due to their solidification cracking tendency. Solidification cracks form due to critical stress and strain states of the dendritic microstructure with interdendritic melt. Despite the high industrial relevance, there are only approaches addressing single aspects of the problem, metallurgically or structurally oriented. The research unit "Solidification Cracking during Laser Beam Welding – High Performance Computing for High Performance Processes" aims at developing quantitative process understanding of the mechanisms of solidification cracking and their relation to process parameters.The sub-project aims at simulating the dynamics of the melt pool with a resolution of about one micron. This is achieved using a numerical model consisting of approximately 109 computational cells that have to be computed for more than 105 time steps. The simulation will model the phase change at melting and solidification, the energy input from the laser, the expansion and contraction, and the heat and mass transport in the melt pool. Simulations of such complexity require the computational power of parallel high-performance systems and can only be realized using optimized parallel algorithms and modern software technologies. In this sub-project, the lattice Boltzmann method (LBM) will be used and extended to correctly capture the various physical effects in the melt pool. Compared to other numerical schemes, the LBM is well-suited for parallel computing and modern computer architectures that include hardware accelerators. The implementation will be based on the HPC framework waLBerla specifically designed for implementing complex multi-physics applications. Using abstraction layers and code generation concepts, software developed with waLBerla is sustainable, i.e., portable to future computer architectures. One of the significant aspects of this project lies in the validation of newly implemented models and algorithms, and in the interoperability with models from the partners in the research unit. This will be achieved via the close cooperation with neighboring sub-projects.

激光焊接作为一种柔性、无接触的连接技术，越来越受到人们的重视。由于具有大熔化范围的合金的凝固开裂倾向，其加工提出了挑战。凝固裂纹的形成是由于枝晶组织与枝晶间熔体的临界应力和应变状态。尽管具有高度的工业相关性，但只有解决问题的单一方面的方法，无论是从结构上还是从功能上。研究单位“激光束焊接过程中的凝固裂纹-高性能工艺的高性能计算”的目的是对凝固裂纹的机理及其与工艺参数的关系进行定量的工艺理解，该分项目的目的是模拟熔池的动态，分辨率约为1微米。这是通过使用由大约109个计算单元组成的数值模型来实现的，这些计算单元必须计算超过105个时间步长。模拟将模拟熔化和凝固时的相变、激光输入的能量、膨胀和收缩以及熔池中的热量和质量传输。如此复杂的模拟需要并行高性能系统的计算能力，并且只能使用优化的并行算法和现代软件技术来实现。在这个子项目中，格子玻尔兹曼方法（LBM）将被使用和扩展，以正确地捕捉在熔池中的各种物理效应。与其他数值方案相比，LBM非常适合并行计算和包括硬件加速器的现代计算机体系结构。实施将基于专门为实施复杂的多物理场应用而设计的HPC框架waLBerla。通过使用抽象层和代码生成概念，使用waLBerla开发的软件是可持续的，即，可移植到未来的计算机架构中。该项目的一个重要方面在于验证新实施的模型和算法，以及与研究单位合作伙伴的模型的互操作性。这将通过与邻近子项目的密切合作来实现。