Abstract In order to maintain the flow uniformity and prevent the ejecting metal powders across the working chamber of Selective Laser Melting (SLM), for the purpose of obtaining the high quality products, flow observations inside the chamber need to be carefully conducted. This study proposed the technique of particle image velocimetry (PIV) for investigating the flow characteristics inside the SLM chamber, with examining two elliptical blowing nozzles with different aspect ratios (ARs). The mean velocity distributions, turbulence intensities, vorticities and Reynolds stress were analyzed to evaluate the performances of the two nozzles, Ellipse 1 and Ellipse 2. The experimental results demonstrated that Ellipse 1 with higher AR were more suitable for SLM operation, owing to the faster velocity decay, the higher spread rate and entrainment and the smaller stagnation region.

中文翻译：

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应用粒子图像测速 (PIV) 实验观察选择性激光熔化 (SLM) 工作室内的流动行为

摘要 为了保持流动的均匀性，防止金属粉末穿过选区激光熔化（SLM）的工作腔，为了获得高质量的产品，需要仔细观察腔内的流动情况。本研究提出了粒子图像测速 (PIV) 技术，用于研究 SLM 室内的流动特性，并检查具有不同纵横比 (AR) 的两个椭圆形吹气喷嘴。分析平均速度分布、湍流强度、涡度和雷诺应力以评估 Ellipse 1 和 Ellipse 2 两个喷嘴的性能。实验结果表明，具有较高 AR 的 Ellipse 1 更适合 SLM 操作，因为速度更快速度衰减，