Numerical modeling of turbulent and laminar airflow and odorant transport during sniffing in the human and rat nose
Numerical modeling of turbulent and laminar airflow and odorant transport during sniffing in the human and rat nose
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DOI：
10.1093/chemse/bjj008
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发表时间：
2006-02-01
期刊：
影响因子：
3.5
通讯作者：
Scherer, PW
中科院分区：
文献类型：
--
作者：
Zhao, K;Dalton, P;Scherer, PW
人的嗅闻行为通常包括短时间、高流量的吸入(通过每个鼻孔300毫升/S)，大部分是湍流气流。这通常被认为是一个因素，能够使更多的气味沉积到嗅黏膜上，而不是层流气流，从而有助于嗅觉检测。然而，使用计算流体力学人体鼻腔模型，我们发现对于湍流和层流，预测的嗅觉气味通量(g/cm(2)S)基本上没有差异，总鼻流率在300到1000毫升/S之间，以及气味在黏膜中的溶解度非常不同。这种差异的缺乏被证明是由于鼻腔粘膜气道壁对侧向气味物质传输的阻力比气相要高得多。模拟还发现，当吸入空气/气味体积保持不变时，增加嗅探过程中的气流速度可以增加鼻/嗅觉黏膜对气味的吸收通量，但会降低嗅觉区的累积总摄取量，这与嗅觉持续时间可能比嗅觉强度更重要的观察结果一致。相比之下，在大鼠身上，嗅觉涉及到层流气流的高频吸气和呼气。在大鼠鼻气味吸收模拟中，观察到气味沉积高度依赖于溶解度，并与不同类型的受体的位置相关。
Human sniffing behavior usually involves bouts of short, high flow rate inhalation (> 300 ml/s through each nostril) with mostly turbulent airflow. This has often been characterized as a factor enabling higher amounts of odorant to deposit onto olfactory mucosa than for laminar airflow and thereby aid in olfactory detection. Using computational fluid dynamics human nasal cavity models, however, we found essentially no difference in predicted olfactory odorant flux (g/cm(2) s) for turbulent versus laminar flow for total nasal flow rates between 300 and 1000 ml/s and for odorants of quite different mucosal solubility. This lack of difference was shown to be due to the much higher resistance to lateral odorant mass transport in the mucosal nasal airway wall than in the air phase. The simulation also revealed that the increase in airflow rate during sniffing can increase odorant uptake flux to the nasal/olfactory mucosa but lower the cumulative total uptake in the olfactory region when the inspired air/odorant volume was held fixed, which is consistent with the observation that sniff duration may be more important than sniff strength for optimizing olfactory detection. In contrast, in rats, sniffing involves high-frequency bouts of both inhalation and exhalation with laminar airflow. In rat nose odorant uptake simulations, it was observed that odorant deposition was highly dependent on solubility and correlated with the locations of different types of receptors.