Inertial and interceptional deposition of spherical particles and fibers in a bifurcating airway

Cai, Feixiang; Yu, C.P.

doi:10.1016/0021-8502(88)90003-1

Cited by 82 publications

(54 citation statements)

References 13 publications

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“…Balásházy et al (1990) have improved the bend model by considering different flow profiles in the bend and by showing ways to adopt a simple bend to the bifurcation geometry. Based on a stopping distance concept, Cai and Yu (1988) showed that inertial deposition in an idealized symmetrical bifurcation is a function of Stokes number, bifurcation angle, and ratio of parent and daughter tube diameters. Deposition equations derived from these models have been used in lung deposition models to predict the deposition pattern in the human respiratory tract.…”

Section: Introductionmentioning

confidence: 99%

Particle Deposition in a Cast of Human Tracheobronchial Airways

Zhou

Cheng

2005

Aerosol Science and Technology

104

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Regional particle deposition efficiency and deposition patterns were studied experimentally in a human airway replica made from an adult cadaver. The replica includes the oral cavity, pharynx, larynx, trachea, and four generations of bronchi. This study reports deposition results in the tracheobronchial (TB) region. Nine different sizes of monodispersed, polystyrene latex fluorescent particles in the size range of 0.93-30 µm were delivered into the lung cast with the flow rates of 15, 30, and 60 l min −1 . Deposition in the TB region appeared to increase with the increasing flow rate and particle size. Comparison of deposition data obtained from physical casts showed agreement with results obtained from realistic airway replicas that included the larynx. Deposition data obtained from idealized airway models or replicas showed lower deposition efficiency. We also compared experimental data with theoretical models based on a simplified bend and bifurcation model. A deposition equation derived from these models was used in a lung dosimetry model for inhaled particles, and we demonstrated that there was general agreement with theoretical models. However, the agreement was not consistent over the large range of Stokes number. The deposition efficiency was found as a function of the Stokes number, bifurcation angle, and the diameters of parent and daughter tubes. An empirical model was developed for the particle deposition efficiency in the TB region based on the experimental data. This model, combined with the oral deposition model developed previously, can be used to predict the particle deposition for inertial effects with improved accuracy.

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Section: Introductionmentioning

confidence: 99%

Particle Deposition in a Cast of Human Tracheobronchial Airways

Zhou

Cheng

2005

Aerosol Science and Technology

104

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“…Vertical lines indicate stage cut-sizes for the MOUDIs used in this experiment. Relatively large particles (D p > 0.56 µm) deposit in the head airways (∼22%) as a result of sedimentation and the impaction of particles onto the larynx and airway bifurcations (Lee and Wang 1975;Wang 1975;Cai and Yu 1988;Zhang and Yu 1993). Deposition of particles with D p < 0.18 µm is primarily governed by Brownian diffusion (Ingham 1984) leading to preferential deposition in the pulmonary region (∼21%) followed by the head airways (∼18%) and then the tracheobronchial region (∼13%).…”

Section: Methodsmentioning

confidence: 99%

Seasonal Variation of Airborne Particle Deposition Efficiency in the Human Respiratory System

Ham

Ruehl

Kleeman

2011

Aerosol Science and Technology

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Particulate matter (PM) is associated with human health effects but the apparent toxicity of PM in epidemiological studies varies with season. PM toxicity may change due to seasonal shifts in composition or particle size distributions that in turn affect respiratory deposition efficiencies. In the current study, size-resolved PM composition was measured in the largest city ( This enhanced deposition would not be detected by routine filter samples because all of the size distribution changes occur at particle diameters <2.5 µm. This study demonstrates that changes to the particle size distributions (<2.5 µm) can enhance respiratory deposition efficiencies for trace metals and/or water-soluble ions and this may contribute to seasonal shifts in PM toxicity.

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“…Previous particle deposition investigations in the oropharyngeal airway have used realistic replicas from cadavers [1], idealized oral models [2] and idealized mouth-throat models [3,4]. In TB airway studies, the effective methods *Corresponding author (email: zhanglz@nankai.edu.cn) include theoretical predictions on symmetrical bifurcation [5], experimental measurements on realistic replicas [6][7][8], Monte Carlo stochastic simulations [9,10] and computational fluid dynamics (CFD) determinate simulations [11,12].…”

Section: Citationmentioning

confidence: 99%

“…The deposition efficiency in two generations is compared with several theoretical models [1,5,17] and experimental data and the results are shown in There are two parts in the second generation, with different dimensions of length and diameter, as well as the bifurcate angle. Thus, multiple Stokes numbers and theoretical lines were applied to comparing the deposition efficiencies in this generation (Figure 3(b)).…”

Section: Particle Deposition Efficiencymentioning

confidence: 99%

Micro-particle deposition and lobar distribution of mass flow in human upper respiratory tract model

Huang

Zhang

2011

Chin. Sci. Bull.

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A representative human upper respiratory tract model consisting of oropharyngeal and asymmetric tracheobronchial (TB) airways from the trachea (G0) to the main lobar bronchi (G2) was constructed. Laminar-to-turbulent airflow for typical inhalation modes as well as micro-particle transportation, wall deposition and mass flow to lobes was simulated using the CFX10.0 software from Ansys Inc. The numerical particle deposition efficiency of the oropharynx region and two generations (G1 and G2) of TB airways shows great agreement with the experimental data obtained from realistic casts. The particle deposition pattern indicates that inertial impaction is the primary mechanism in the human upper airway, and turbulence dispersion performs crescent influence especially for small particles. The initial positions of particles with different fates are confined to specifically concentrated zones. The particle mass distributions of five lobes are close to airflow distributions. The upper lobes receive fewer particles than lower lobes and the right middle lobe receives the least.upper respiratory tract, asymmetric tracheobronchial airways, transportation and deposition, lobar differences, computational fluid dynamics simulation Citation:Huang J H, Zhang L Z. Micro-particle deposition and lobar distribution of mass flow in human upper respiratory tract model. Chinese Sci Bull, 2011Bull, , 56: 380−385, doi: 10.1007 Inhaled particle deposition in the human respiratory tract is a concern in lung diseases. Accurate investigation of aerosol deposition in the human upper respiratory tract (URT) and lobar distribution are important for the analysis of "filtering effects" of human URT and correct air/particle inlet conditions to the deeper bronchial airways. The human upper respiratory tract consists of the oral cavity, nasal cavity, pharynx/larynx airway and tracheobronchial (TB) airways. Numerous investigations have been carried out in experimental or numerical methods on one part or several parts of the human respiratory tract. Previous particle deposition investigations in the oropharyngeal airway have used realistic replicas from cadavers [1], idealized oral models [2] and idealized mouth-throat models [3,4]. In TB airway studies, the effective methods *Corresponding author (email: zhanglz@nankai.edu.cn) include theoretical predictions on symmetrical bifurcation [5], experimental measurements on realistic replicas [6][7][8], Monte Carlo stochastic simulations [9,10] and computational fluid dynamics (CFD) determinate simulations [11,12].Most studies have focused on one part or several separated parts of human URT, but a few studies investigate the particle deposition in the whole region of human URT [13] or predict the lobar distribution of air and particle mass flow into the five lobes. Whole region URT studies avoid any assumptions of boundary conditions between separate parts. A more precise human URT model will improve the accuracy of prediction.In this study, we construct a representative human URT model with oropharyngeal a...

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Inertial and interceptional deposition of spherical particles and fibers in a bifurcating airway

Cited by 82 publications

References 13 publications

Particle Deposition in a Cast of Human Tracheobronchial Airways

Particle Deposition in a Cast of Human Tracheobronchial Airways

Seasonal Variation of Airborne Particle Deposition Efficiency in the Human Respiratory System

Micro-particle deposition and lobar distribution of mass flow in human upper respiratory tract model

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