Abstract Accurate predictions of aerosol transport, evolution, and deposition in the human airways are crucial for inhalation dosimetry investigations. Inhaled aerosol transported through the airways undergoes thermodynamic changes due to changes in temperature and humidity. Aerosol evolution processes are particularly important for liquid multispecies aerosols. These aerosols are sensitive to condensation and/or evaporation dynamics, which can modify gas/liquid partitioning of each species and particle size distribution. In this manuscript, we present computational fluid dynamics simulations of complex aerosol mixtures in a realistic geometry of the human respiratory tract cast model. We used a publicly available computational framework, AeroSolved, developed for simulation of evolving multispecies aerosol mixtures. We evaluated the dynamics of liquid particles in physiologically relevant conditions of 100 % relative humidity at the temperature of 37 ° C . We studied two separate inhalation flow scenarios: in the first case, a warm aerosol at 50 ° C was inhaled and subsequently cooled down while flowing in the airways. In the second case, an aerosol at room temperature was inhaled and heated up to the temperature of 37 ° C . Our results demonstrated that aerosol evolution mainly occurs in the upper segments of the airways (throat and trachea) at the very short timescales. Apart from showing the significant influence of temperature and humidity conditions on aerosol dynamics and evolution, we also measured aerosol deposition fluxes investigating the dependence of the delivered aerosol mass on evolution mechanisms. We showed that the delivered regional mass of each species depends on the physico-chemical properties of the mixture, and it is also significantly influenced by the airways’ humidity and thermal conditions. It was also shown that the species-specific properties of the liquid mixture (e.g., activity coefficient) play an important role in gas/liquid partitioning of the species. With AeroSolved such dependencies can be further investigated with greater attention towards specific needs and physiologically important conditions (e.g., transient flow inhalation patterns, aerosol mixture composition and its properties).

中文翻译：

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人类呼吸道模型中的多物种气溶胶演变和沉积

摘要 准确预测气溶胶在人体气道中的运输、演化和沉积对于吸入剂量学研究至关重要。由于温度和湿度的变化，通过气道输送的吸入气溶胶会发生热力学变化。气溶胶演化过程对于液体多物种气溶胶尤为重要。这些气溶胶对冷凝和/或蒸发动力学很敏感，这可以改变每个物种的气/液分配和粒度分布。在这份手稿中，我们在人体呼吸道模型的真实几何形状中展示了复杂气溶胶混合物的计算流体动力学模拟。我们使用了一个公开可用的计算框架 AeroSolved，它是为模拟不断发展的多物种气溶胶混合物而开发的。我们在 100% 相对湿度和 37°C 的温度下评估了液体颗粒在生理相关条件下的动力学。我们研究了两种不同的吸入流情景：在第一种情况下，吸入 50 °C 的温暖气溶胶，随后在气道中流动时冷却。在第二种情况下，吸入室温气溶胶并加热至 37°C 的温度。我们的结果表明，气溶胶演化主要发生在气道的上段（喉咙和气管）在很短的时间尺度上。除了显示温度和湿度条件对气溶胶动力学和演化的显着影响外，我们还测量了气溶胶沉积通量，研究了传递的气溶胶质量对演化机制的依赖性。我们表明，每个物种的区域质量取决于混合物的理化性质，并且还受到气道湿度和热条件的显着影响。还表明，液体混合物的物种特异性特性（例如，活度系数）在物种的气/液分配中起重要作用。使用 AeroSolved 可以进一步研究此类依赖性，同时更加关注特定需求和重要生理条件（例如，瞬态流吸入模式、气溶胶混合物成分及其特性）。还表明，液体混合物的物种特异性特性（例如，活度系数）在物种的气/液分配中起重要作用。使用 AeroSolved 可以进一步研究此类依赖性，同时更加关注特定需求和重要生理条件（例如，瞬态流吸入模式、气溶胶混合物成分及其特性）。还表明，液体混合物的物种特异性特性（例如，活度系数）在物种的气/液分配中起重要作用。使用 AeroSolved 可以进一步研究此类依赖性，同时更加关注特定需求和重要生理条件（例如，瞬态流吸入模式、气溶胶混合物成分及其特性）。