Department of Otorhinolaryngology: Head and Neck Surgery, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea.
Department of Mechanical Engineering, Konkuk University, Seoul, Republic of Korea.
Respir Physiol Neurobiol. 2021 Aug;290:103674. doi: 10.1016/j.resp.2021.103674. Epub 2021 Apr 21.
The dynamic characteristics of air-conditioning in the human nasal cavity during a respiratory cycle were investigated using unsteady numerical simulations to assess whether inhaled air is sufficiently conditioned by the nasal cavity. Variations in the epithelial surface temperature, surface heat, and water vapor fluxes were found to vary significantly during inspiration while providing substantial air conditioning to the inhaled air, but variations and magnitudes were significantly reduced during the expiration period. Air temperature (31.3-35.3 °C) and relative humidity (85.1-100 %) in the nasopharynx exhibited significant variations during inspiration. Flow rate-weighted average values of the air temperature and relative humidity during inspiration were estimated to be 32.0 °C and 89.1 %, respectively. Inhaled air did not attain alveolar conditions before reaching the nasopharynx, and was therefore thought to be insufficiently conditioned by the nasal cavity alone. A steady flow of approximately 250 mL/s appears to be useful for evaluating the accumulated thermal state of air in the nasopharynx during inspiration.
采用非稳态数值模拟研究了呼吸周期中人体鼻腔内空调的动态特性，以评估鼻腔是否能充分调节吸入的空气。结果发现，在吸气过程中，上皮表面温度、表面热量和水蒸气通量的变化差异显著，这为吸入的空气提供了充分的空气调节作用，但在呼气期间，这些变化和幅度显著减小。在吸气过程中，鼻咽部的空气温度（31.3-35.3°C）和相对湿度（85.1-100%）均呈现显著变化。吸气过程中，空气温度和相对湿度的流量加权平均值分别估计为 32.0°C 和 89.1%。吸入的空气在到达鼻咽部之前并未达到肺泡条件，因此被认为仅通过鼻腔进行的空气调节是不充分的。在吸气过程中，大约 250mL/s 的稳定流量似乎可用于评估鼻咽部内空气的累积热状态。
