Air curtain is an efficient device for cutting off airflow and confining contaminants. Inspired by the ability, a circulated air curtain composed of end-to-end plane jets generated by a relay of air pillars is proposed to confine exhaled contaminants in this study. Furthermore, the optimization study of computational fluid dynamics (CFD) is conducted to explore cutting-off performance and find better design parameters under different conditions, i.e., human-curtain distance, enclosure shape, jet velocity from air pillar, and exhalation modes. The multidirectional blockage and vortex-like rotative transmission routes of exhaled airflow are observed when air curtain exists. Results indicate that contaminants are concentrated around the source. The average mole fraction of exhaled contaminants outside air curtain under different human-curtain distance decreases 4.3%–19.6% compared to mixing ventilation with same flux. Shortening the human-curtain distance can improve the performance of air curtain and may change the direction of exhaled airflow. Moreover, It has better performance when the enclosure shape is close to a circle. Higher jet velocity is better for improving the confinement performance, but the trend is not very obvious as velocity increases. For exhalation modes, it is more challenging to control exhaled contaminants for intense exhalation activity (such as coughing) in steady simulation, but results in transient simulation show better performance when coughing only once. These results can provide a reference for the subsequent design and improvement in applying air curtain in hospital wards or other places, especially during the period of flu outbreak.

空气幕是一种有效的截断气流和限制污染物的装置。受该能力的启发，本研究提出了一种由气柱中继产生的端到端平面射流组成的循环气幕，以限制呼出的污染物。此外，还对计算流体动力学（CFD）进行了优化研究，以探索截止性能，并在不同条件下找到更好的设计参数，即人帘距离、外壳形状、气柱喷射速度和呼气模式。存在气幕时，可观察到呼出气流的多向阻塞和涡旋状的旋转传播路径。结果表明污染物集中在源头周围。与相同通量的混合通风相比，不同人帘距离下空气幕外呼出污染物的平均摩尔分数降低了4.3%~19.6%。缩短人帘距离可以提高气帘的性能，并可能改变呼出气流的方向。此外，当外壳形状接近圆形时，它具有更好的性能。较高的射流速度有利于改善约束性能，但随着速度的增加趋势不是很明显。对于呼气模式，在稳定模拟中控制呼出污染物以实现强烈的呼气活动（例如咳嗽）更具挑战性，但瞬态模拟的结果在仅咳嗽一次时表现出更好的性能。