The deposition efficiency of unsteady inhalation is investigated in present study by using computational fluid dynamics techniques. Comparison with steady inhalation is also discussed. The inspiratory cycle of a realistic unsteady inhalation profile was applied at the outlet of nasopharynx, which has the maximum flow rate of 40.3L/min. Aerodynamic particle sizes of 5μm and 20μm were studied in ...

In this work the steady-state flow in a commercial dry powder inhaler device, DPI (i.e., Turbuhaler) is described using computational fluid dynamics. The Navier-Stokes equations are solved using commercial CFD software considering different flow models, i.e., laminar, k-ε, k-ε RNG, and k-ω SST as well as large Eddy simulation. Particle motion and deposition are described using a Eulerian-fluid/...

Accurate prediction of particle deposition indoors is important to estimate exposure risk of building occupants to particulate matter. The prediction requires accurate modeling of airflow, turbulence, and interactions between particles and eddies close to indoor surfaces. This study used a 2 ′ − v f turbulence model with a modified Lagrangian method to predict the particle deposition in enclose...

The pattern of deposition within the respiratory tract of potentially harmful particulates is a major factor in assessing any risk from individual and community exposures. Although the trachea is the most easily observed of the conductive airways, very little information concerning its particle collection characteristics is available, information which is essential for a complete and realistic ...

Effective management of asthma is dependent on achieving adequate delivery of the drugs into the lung. Inhalers come in the form of dry powder inhalers (DPIs) and metered dose inhalers (pMDIs) with the former requiring a deep fast breath for activation while there are no restrictions on inhalation rates for the latter. This study investigates two aerosol medication delivery methods (i) an ideal...

Anatomically accurate computational fluid dynamics (CFD) models of the nasal passages of an infant (6 months old, 1.3 kg) and adult (7 years old, 11.9 kg) rhesus monkey were used to predict nasal deposition of inhaled nano- and microparticles. Steady-state, inspiratory airflow simulations were conducted at flow rates equal to 100, 200 and 300% of the estimated minute volume for resting breathin...

Theoretical models of respiratory tract deposition of inhaled particles are compared to experimental studies of deposition patterns in humans and animals, as governed principally by particle size, density, respiratory rate and flow parameters. Various models of inhaled particle deposition make use of approximations of the respiratory tract to predict fractional deposition caused by fundamental ...

The deposition of aerosol in the lung is an important issue regardless of whether the aerosol results from airborne pollutants or aerosol therapy. The specific pattern of deposition of airborne pollutants is a determinant in the development of pulmonary diseases since this pattern determines the local doses in the airspaces and the subsequent redistribution and clearance of the deposited partic...

Accurate prediction of particle deposition in airliner cabins is important for estimating the exposure risk of passengers to infectious diseases. This study developed a Detached-Eddy Simulation (DES) model with a modified Lagrangian method. The computer model was validated with experimental data for particle deposition in a cavity with natural convection and with air velocity, air temperature, ...

The deposition of particles in fully-developed turbulent channel flow has been calculated using large eddy simulation of the incompressible Navier-Stokes equations. Calculations were performed for Reynolds numbers of 11,160 and 79,400 (based on bulk velocity and hydraulic diameter); subgrid-scale stresses were parameterized using the dynamic eddy viscosity model. Particle motion was governed by...