FLOW AND PARTICLE DEPOSITION IN THE TURBUHALER DPI A CFD Simulation

In this work the steady-state flow in a commercial dry powder inhaler device (i.e.., Turbuhaler) is described. The DPI geometry is constructed in a CAD/CAM environment (i.e., CATIA v5) and then imported into GAMBIT where the geometry is discretized into a computational grid. The Navier-Stokes equations are solved using FLUENT (v6.3) and particle motion and deposition are described using an Eulerian-fluid/Lagrangian-particle approach. Flow and particle deposition for a range of mouthpiece pressure drops (i.e., 800-8800Pa), as well as particle sizes corresponding to single particles and aggregates (i.e., 0.5-20 mu m) are examined. The total volumetric outflow rate, the overall particle deposition as well as the particle deposition sites in the DPI are determined. The simulation results are found to agree well with available experimental data for volumetric flow and overall particle deposition.