Metal additive manufacturing via laser-based powder bed fusion (PBF-LB/M) faces performance-critical challenges due to complex melt pool and vapor dynamics, often oversimplified by computational models that neglect crucial aspects, such as vapor jet formation. To address this limitation, we propose a consistent computational multi-physics mesoscale model to study melt pool dynamics, laser-induced evaporation, and vapor flow. In addition to the evaporation-induced pressure jump, we also resolve the evaporation-induced volume expansion and the resulting velocity jump at the liquid--vapor interface. We use an anisothermal incompressible Navier--Stokes solver extended by a conservative diffuse level-set framework and integrate it into a matrix-free adaptive finite element framework. To ensure accurate physical solutions despite extreme density, pressure and velocity gradients across the diffuse liquid--vapor interface, we employ consistent interface source term formulations developed in our previous work. These formulations consider projection operations to extend solution variables from the sharp liquid--vapor interface into the computational domain. Benchmark examples, including film boiling, confirm the accuracy and versatility of the model. As a key result, we demonstrate the model's ability to capture the strong coupling between melt and vapor flow dynamics in PBF-LB/M based on simulations of stationary laser illumination on a metal plate. Additionally, we show the derivation of the well-known Anisimov model and extend it to a new hybrid model. This hybrid model, together with consistent interface source term formulations, especially for the level-set transport velocity, enables PBF-LB/M simulations that combine accurate physical results with the robustness of an incompressible, diffuse-interface computational modeling framework.

翻译：基于激光的粉末床熔融金属增材制造面临性能关键挑战，这源于复杂的熔池和蒸汽动力学，而现有计算模型常因忽略蒸汽射流形成等关键方面而过度简化。为克服此局限，我们提出一种一致的计算多物理场介观尺度模型，用于研究熔池动力学、激光诱导蒸发及蒸汽流动。除蒸发诱导的压力跃变外，我们还解析了蒸发诱导的体积膨胀及其在液-汽界面产生的速度跃变。我们采用基于保守扩散水平集框架扩展的非等温不可压缩Navier-Stokes求解器，并将其集成至无矩阵自适应有限元框架中。为确保在扩散液-汽界面存在极端密度、压力和速度梯度时仍能获得精确物理解，我们采用先前工作中开发的一致性界面源项公式。这些公式通过投影操作将解变量从尖锐液-汽界面扩展至计算域。包括膜态沸腾在内的基准算例验证了模型的准确性与通用性。作为关键成果，我们基于金属板上静止激光照射的仿真，证明了该模型捕捉PBF-LB/M中熔融与蒸汽流动动力学强耦合的能力。此外，我们展示了经典Anisimov模型的推导过程，并将其扩展为新型混合模型。该混合模型与一致性界面源项公式（特别是针对水平集输运速度的公式）相结合，使得PBF-LB/M仿真能够在保持精确物理结果的同时，兼具不可压缩扩散界面计算建模框架的鲁棒性。