This work proposes an extension of phase change and latent heat models for the simulation of metal powder bed fusion additive manufacturing processes on the macroscale and compares different models with respect to accuracy and numerical efficiency. Specifically, a systematic formulation of phase fraction variables is proposed relying either on temperature- or enthalpy-based interpolation schemes. Moreover, two well-known schemes for the numerical treatment of latent heat, namely the apparent capacity and the so-called heat integration scheme, are critically reviewed and compared with respect to numerical efficiency and overall accuracy. Eventually, a novel variant of the heat integration scheme is proposed that allows to directly control efficiency and accuracy by means of a user-defined tolerance. Depending on the chosen tolerance, it is shown that this novel approach offers increased numerical efficiency for a given level of accuracy or improved accuracy for a given level of numerical efficiency as compared to the apparent capacity and the original heat integration scheme. The investigation and comparison of all considered schemes is based on a series of numerical test cases that are representative for application scenarios in metal powder bed fusion additive manufacturing.

中文翻译：

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金属增材制造过程仿真中的相变和潜热模型

这项工作提出了相变和潜热模型的扩展，用于在宏观上模拟金属粉末床熔融添加剂制造过程，并就准确性和数值效率进行了比较。具体而言，提出了一种基于温度或焓的插值方案的相分数变量的系统公式。此外，对潜热进行数值处理的两个众所周知的方案，即视在容量和所谓的热积分方案，经过严格审查，并就数值效率和整体精度进行了比较。最终，提出了一种热集成方案的新颖变体，该变体允许通过用户定义的公差直接控制效率和精度。根据所选的公差，结果表明，与视在容量和原始热积分方案相比，对于给定的精度水平，此新颖方法可提供更高的数值效率，对于给定的数字效率水平，可提供更高的精度。所有考虑方案的调查和比较都是基于一系列数值测试案例，这些案例代表了金属粉末床熔融添加剂制造中的应用场景。