不同空调环境下鼻腔内环境的数值模拟

Numerical Simulation of Airflow in Nasal Cavity under Different Air Conditions

鼻腔作为与外界环境直接相连的呼吸器官,其内环境极易受外界环境影响改变而引起不适或加重疾病风险,因此对人体长时间暴露的空调环境下鼻腔内环境的研究很有必要。为了研究不同空调环境下的吸入气流对鼻腔温湿度调节功能的影响,根据健康人体CT扫描切片重建3D鼻腔模型,利用Transition SST湍流模型和组分输运模型进行数值计算,得到了鼻腔内详细的气流速度场、温度场、相对湿度场分布,结果显示在温度(temperature, T)和相对湿度(relative humidity, RH)分别为18℃/30%、24℃/50%和28℃/70%的典型空调环境工况下,较为低温低湿的空调环境使鼻腔内部存在更大的低温干燥区;18℃条件下鼻腔内环境有63%的区域温度低于33℃;18℃/30%RH条件下呼吸蒸发水量是28℃/70%RH下的1.73倍;在咽部出口处吸入气流基本能被调节至满足进入下呼吸道的条件。可见室内空调工况对鼻腔内环境存在影响,较低湿度和温度的室内环境增加鼻腔调节负荷;本文应用的数值模拟方法可以较为准确且快速地模拟人体鼻腔内的气流及热湿交换,可应用于不同环境对鼻咽功能结构影响的量化评价及辅助临床评估诊断。

The nasal cavity is directly connected to the external environment, and its internal environment is easily changed by external influences to cause discomfort or aggravate the risk of disease. It is necessary to study the internal environment of the nasal cavity under the air-conditioned environment exposed to the human body for a long time. In order to investigate the effects of inhaled airflow in different air-conditioned environments on the temperature and humidity adjustment function of nasal cavity, a model was reconstructed by the CT images of a healthy human nasal cavity, and the Transition SST turbulence model and component transport model was applied to obtain the distribution of airflow velocity, temperature and humidity in the nasal. The results show that under typical air conditioning conditions of 18 ℃/30%, 24 ℃/50%, 28 ℃/70%, the nasal cavity can adjust the inhaled air to the conditions of the lower respiratory tract, but the nasal cavity has a larger cold-dry zone under low temperature and humidity environment. At 18 ℃, 63% of the nasal cavity environment temperature is lower than 33 ℃. The amount of respiratory evaporation at 18 ℃/30%RH is 1.73 times that at 28 ℃/70%RH. It is concluded that lower humidity and temperature increase the burden of nasal regulation. The numerical simulation method presented in this paper can be used as an auxiliary means for clinical diagnosis of nasopharyngeal structure and function.