环境因素对外耳道湿度影响的数值模拟分析  

Numerical flow simulation in the humidity of external auditory canal

作　　者：庄惠文[1] 黎建峰[2] 王东芳[1] 熊观霞[1] 

机构地区：[1]中山大学附属第一医院耳鼻咽喉科医院耳鼻咽喉科研究所,广州510080 [2]中山大学应用力学与工程系

出　　处：《中华生物医学工程杂志》2017年第2期139-144,共6页Chinese Journal of Biomedical Engineering

基　　金：广东省自然科学基金（2015A030313094）

摘　　要：目的 通过计算流体力学（CFD）的方法研究外耳道气流的特点,探讨环境因素对外耳道湿度的影响,为外耳道部分生理及病理现象提供初步的理论依据.方法 通过病史、耳镜、耳内镜、中耳分析仪筛选出一例研究对象,用CFD的方法计算稳定状态下的外耳道气流温度、速度和湿度特点,分析环境因素（气流速度、温度和湿度）对外耳道气流湿度的影响.结果 在外耳道皮肤释放水蒸气的速率为1.557x10-6 kg/m2s、外界温度20℃、环境湿度5.991 g/m3、环境风速0.25 m/s情况下,外耳道气流的平均温度为34.01℃;外耳道区域的平均气流速度为4.6x10-4 m/s;外耳道区域的平均湿度为18.963 g/m3,湿度从里向外逐渐减小,环境温度的下降（温差的增大）,外耳道湿度降低.当环境风速小于0.5时,外耳道湿度只是发生轻微变化,之后随着环境气流速度的增大,外耳道湿度快速下降.外耳道湿度随着环境湿度同步上升.结论 外耳道是一个相对闭塞的区域,气流速度极低,温度与人体温度非常接近,湿度呈现从里向外梯度减少.外耳道湿度随着环境风速的增大而降低;环境温度通过改变气流影响外耳道的湿度,但影响的幅度不大;外耳道湿度随环境湿度同步上升.Objective To determine the influence of environmental factors on the external auditory canal humidity through the characteristics of external auditory canal flow calculated via computational fluid dynamics （CFD）,and to provide the preliminary theoretical basis for the physiological and pathological phenomena of the external auditory canal. Methods A study case was selected by review of history,and findings of otoscopy,ear endoscopy,acoustic immittance measurement and CT scanning. CFD method was used to calculate the temperature,velocity and humidity characteristics of the external auditory canal in steady state. The effects of environmental factors（such as airflow velocity,temperature and humidity）on the external auditory canal airflow humidity were analyzed. Results The average temperature of the external auditory canal was 34.01℃when the rate of water vapor released from the external auditory canal was 1.557＆#215; 10-6 kg/m2s,the ambient temperature was 20℃,the ambient humidity was 5.991 g/m3 and the ambient wind speed was 0.25 m/s. The average airflow velocity in the external auditory canal area was 4.6 ＆#215; 10-4 m/s;the average humidity in the external auditory canal region was 18.963 g/m3. The humidity presented a gradient-reducing feature from inside to the outside. Reduced ambient temperature （and thereby an increase in the temperature difference） led to decreased external auditory canal humidity. The external auditory canal humidity showed only minimal change when the ambient wind speed was less than 0.5 m/s,and then decreased rapidly along with increasing ambient airflow velocity. The external auditory canal humidity increasedsynchronously with the ambient humidity. Conclusions The external auditory canal is a relatively occluded area with a very low-speed airflow,a temperature close to the human body temperature,and a humidity decreasing from the inside to the outside. The external auditory canal humidity decreases with the increase in the ambient wind speed. The ambient temperatur

关 键 词：耳道 微流体分析技术 湿度 

分 类 号：R764[医药卫生—耳鼻咽喉科] TP391.9[医药卫生—临床医学]