外界温度对鼻腔气流影响的数值模拟研究

目的 采用数值模拟技术研究在不同外界温度下,健康成年人鼻腔鼻窦的气流流场特点.方法 根据健康成年人鼻腔鼻窦CT扫描,利用计算流体力学软件Fluent建立正常的鼻腔模型,模拟周期性呼吸下,外界温度在0℃、24℃、37℃时鼻腔的气流状况,计算并分析不同温度下鼻腔气流场参数的异同.结果 周期性呼吸下,吸气相加速区与减速区的鼻腔温度分布不完全对称,吸气加速区温度大于减速区,越靠近过渡点相同流量下加速区与减速区差异越大;呼气相鼻腔温度比较平稳;无论吸气和呼气相,各鼻窦温度分布基本保持一致.外界温度在0℃和24℃时,鼻腔的加温作用主要位于鼻腔前部;鼻腔吸气相的气流速度明显不同,但各鼻道的气流比例、流线差异不大;外界温度对呼气相鼻腔主要通道的气流运动影响很小.外界温度在0℃、24C、37C时,每个呼吸周期内鼻窦气流平均速度的变化都相近,但温差增大了鼻窦内气体的无规则流动.结论 外界温度影响吸气相鼻腔的温度和鼻腔主要通道的气流速度,温差增大了鼻窦内气体的无规则流动.

Numerical simulation study on effects of ambient temperature on airflow in the nasal cavity

Objective To study the aerodynamics of the normal human nasal cavity under different ambient temperatures.Methods Based on CT scanning,a model of a healthy adult's nasal cavity was established using computational fluid dynamics software from Fluent.Airflow in this model was simulated and calculated at ambient temperatures of 0℃,24℃,and 37℃ during periodic breathing.Results Ambient temperature only had an impact on the temperature in the nasal cavity during the inspiratory phase,and the temperature distribution was not symmetrical in the inspiratory acceleration and deceleration phases.The ambient temperature significantly affected airflow speed in main nasal passages during the inspiratory process,but had little impact on flow status (proportion and streamline of airflow in different nasal passages).Temperature differences increased the irregular air movement within sinuses.The anterior nasal segment,including the area between the valve and the head of the middle turbinate,was the most effective part of the nasal airway in heating the ambient air.Conclusions Our findings describe the effects of ambient temperature on airflow parameters in the nasal cavity within a single respiratory cycle.This data is more comprehensively and accurately to determine the relationship between nasal cavity aerodynamics and physiological functions.