Faculty of Engineering Sciences, Kyushu University, Kasuga-koen, Kasuga, Fukuoka, Japan.
International Centre for Indoor Environment and Energy, Technical University of Denmark, Kongens Lyngby, Denmark.
Indoor Air. 2022 Feb;32(2):e13003. doi: 10.1111/ina.13003.
The breathing zone of an individual indoors is usually defined as a finite region steadily formed in front of a face. Assuming the steady formation of the breathing zone, we propose a procedure for quantitatively identifying a breathing zone formed in front of a human face in the transient condition. This assumption is reasonable considering that the ventilation time scale of human respiration is sufficiently short compared to the ventilation time scale of a room. We used steady-state computational fluid dynamics (CFD) and a computationally simulated person (CSP). We present the probabilistic size of the breathing zone for various postures and breathing conditions. By analyzing unsteady inhalation and exhalation airflow characteristics via a CSP with a respiratory system, we also estimated the direct re-inhalation rate of the exhaled air. The results can be used for developing methods to control the long-term and low-contaminant concentration exposures.
室内个体的呼吸区域通常被定义为在面部前方稳定形成的有限区域。假设呼吸区域的稳定形成，我们提出了一种在瞬态条件下定量识别人体前方呼吸区域的方法。考虑到人类呼吸的通风时间尺度与房间的通风时间尺度相比足够短，这种假设是合理的。我们使用稳态计算流体动力学（CFD）和计算模拟人（CSP）。我们为各种姿势和呼吸条件展示了呼吸区域的概率大小。通过对带有呼吸系统的 CSP 进行吸气和呼气气流特性的非稳态分析，我们还估计了呼出空气的直接再吸入率。研究结果可用于开发控制长期低污染物浓度暴露的方法。
