Shi H, Kleinstreuer C, Zhang Z
Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695-7910, USA.
J Biomech Eng. 2006 Oct;128(5):697-706. doi: 10.1115/1.2244574.
The transport and deposition of nanoparticles, i.e., dp = 1-2 nm, or equivalent vapors, in the human nasal cavities is of interest to engineers, scientists, air-pollution regulators, and healthcare officials alike. Tiny ultrafine particles, i.e., dp < or = 5 nm, are of special interest because they are most rapidly absorbed and hence have an elevated toxic or therapeutic impact when compared to larger particles. Assuming transient laminar 3-D incompressible flow in a representative human nasal cavity, the cyclic airflow pattern as well as local and overall nanoparticle depositions were computationally simulated and analyzed. The focus was on transient effects during inhalation/exhalation as compared to the steady-state assumption typically invoked. Then, an equation for a matching steady-state inhalation flow rate was developed that generates the same deposition results as cyclic inhalation. Of special interest is the olfactory region where the narrow channel surfaces receive only about one-half of a percent of the inhaled nanoparticles because the airflow bypasses these recesses located in the superior-most portions in the geometrically complex nasal cavities.
纳米颗粒（即直径dp = 1 - 2纳米）或等效蒸汽在人类鼻腔中的传输和沉积，受到工程师、科学家、空气污染监管者以及医疗保健官员的关注。微小的超细颗粒（即dp≤5纳米）尤其令人关注，因为它们吸收速度最快，因此与较大颗粒相比，具有更高的毒性或治疗作用。假设在具有代表性的人类鼻腔中存在瞬态层流三维不可压缩流动，对周期性气流模式以及纳米颗粒的局部和整体沉积进行了计算模拟和分析。重点是与通常采用的稳态假设相比，吸入/呼出过程中的瞬态效应。然后，推导了一个匹配稳态吸入流速的方程，该方程产生的沉积结果与周期性吸入相同。特别值得关注的是嗅觉区域，在该区域，狭窄的通道表面仅接收约0.5%的吸入纳米颗粒，因为气流绕过了位于几何形状复杂的鼻腔最上部的这些凹陷处。
