title: Deposition and fine particle production during dynamic flow in a dry powder inhaler: a CFD approach.
abstract: In this work the dynamic flow as well as the particle motion and deposition in a commercial dry powder inhaler, DPI (i.e., Turbuhaler) is described using computational fluid dynamics, CFD. The dynamic flow model presented here is an extension of a steady flow model previously described in Milenkovic et al. (2013). The model integrates CFD simulations for dynamic flow, an Eulerian-fluid/Lagrangian-particle description of particle motion as well as a particle/wall interaction model providing the sticking efficiency of particles colliding with the DPI walls. The dynamic flow is imposed by a time varying outlet pressure and the particle injections into the DPI are assumed to occur instantaneously and follow a prescribed particle size distribution, PSD. The total particle deposition and the production of fine particles in the DPI are determined for different peak inspiratory flow rates, PIFR, flow increase rates, FIR, and particle injection times. The simulation results for particle deposition are found to agree well with available experimental data for different values of PIFR and FIR. The predicted values of fine particle fraction are in agreement with available experimental results when the mean size of the injected PSD is taken to depend on the PIFR.
authors.affiliation: CPERI, CERTH, 6th km Harilaou-Thermi rd., Thermi, Greece; Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece. Electronic address: jovbor@cperi.certh.gr.
authors.forename: J
authors.initials: J
authors.lastname: Milenkovic
authors.affiliation: CPERI, CERTH, 6th km Harilaou-Thermi rd., Thermi, Greece. Electronic address: aleck@cperi.certh.gr.
authors.forename: A H
authors.initials: AH
authors.lastname: Alexopoulos
authors.affiliation: CPERI, CERTH, 6th km Harilaou-Thermi rd., Thermi, Greece; Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece; Department of Chemical Engineering, The Petroleum Institute, Abu Dhabi, United Arab Emirates. Electronic address: cypress@cperi.certh.gr.
authors.forename: C
authors.initials: C
authors.lastname: Kiparissides
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols; D003198:Computer Simulation; D058995:Dry Powder Inhalers; D004867:Equipment Design; D057446:Hydrodynamics; D008962:Models, Theoretical; D010316:Particle Size; D011208:Powders; D013997:Time Factors
chemical_list: D000336:Aerosols; D011208:Powders
keywords: CFD; DEM; DPI; Deposition; Dry powder inhaler; Dynamic; FIR; FPF; Fine particle fraction; HPLC; PIFR; PSD; SST; Turbuhaler; UV spectrophotometer; UVS; computational fluid dynamics; discrete element method; dry powder inhaler; fine particle fraction; flow increase rate; high performance liquid chromatography; particle size distribution; peak inspiratory flow rate; shear-stress transport