Abstract：
People constantly move their heads during conversation, as such movement is an important non-verbal mode of communication. Head movement alters the direction of people\'s expired air flow, therefore affecting their conversational partners\' level of exposure. Nevertheless, there is a lack of understanding of the mechanism whereby head movement affects people\'s exposure. In this study, a dynamic meshing method in computational fluid dynamics was used to simulate the head movement of a human-shaped thermal manikin. Droplets were released during the oral expiration periods of the source manikin, during which it was either motionless, was shaking its head or was nodding its head, while the head of a face-to-face target manikin remained motionless. The results indicate that the target manikin had a high level of exposure to respiratory droplets when the source manikin was motionless, whereas the target manikin\'s level of exposure was significantly reduced when the source manikin was shaking or nodding its head. The source manikin had the highest level of self-exposure when it was nodding its head and the lowest level of self-exposure when its head was motionless. People\'s level of exposure during close contact is highly variable, highlighting the need for further investigations in more realistic conversational scenarios.
摘要：
人们在谈话中不断移动他们的头，因为这种运动是一种重要的非语言交流方式。头部运动改变了人们过期气流的方向,因此会影响他们的对话伙伴的接触水平。然而，人们对头部运动影响人们暴露的机制缺乏了解。在这项研究中,使用计算流体动力学中的动态网格方法来模拟人形热人体模型的头部运动。在来源人体模型的口服到期期间释放液滴，在此期间，它要么一动不动，摇摇头或点头，而面对面目标人体模型的头部一动不动。结果表明，当源人体模型静止时，目标人体模型对呼吸液滴的暴露水平很高，而当源人体模型摇晃或点头时，目标人体模型的暴露水平显着降低。来源人体模型在点头时的自我暴露水平最高，而在头部一动不动时的自我暴露水平最低。人们在密切接触期间的暴露水平是高度可变的，强调需要在更现实的对话场景中进行进一步调查。
