Flow structures and particle deposition patterns in double-bifurcation airway models. I: Air flow fields (Q2731232)

The model geometry, flow structure, particle deposition patterns and air flow are investigated by using double-bifurcation airway models. The air flow is assumed to be steady, incompressible and laminar, and the tubular double bifurcated airways are three-dimensional, rigid and smooth, with rounded as well as sharp carinal ridges for symmetric planar and rounded carinas for \(90^\circ\) nonplanar configurations. The authors obtain numerical results by using a single bifurcation finite volume code CFX (AEA Technology); the corresponding user-enhanced FORTRAN programs are validated with experimental data on velocity profiles. The resulting air flow structure is computed in a wide range of Reynolds numbers \((500\leq \text{Re}_D\leq 2000)\). NEWLINENEWLINENEWLINEThe presented computer analysis of existing multi-generational respiratory models provides insight into complex flow patterns in the human respiratory airways. In particular, the authors calculate sequential pressure drops due to viscous effects, and demonstrate that the Pedley formula for energy dissipation rate can be successfuly employed to predict viscous pressure drops in the daughter tubes. The results of this paper can be very useful for the development of global algebraic lung models.