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Deposition of charged nano-particles in the human airways including effects from cartilaginous rings

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DOI: 10.4236/ns.2011.310113    4,512 Downloads   7,713 Views   Citations

ABSTRACT

This paper presents a numerical study of the deposition of spherical charged nano-particles caused by convection, Brownian diffusion and electrostatics in a pipe with a cartilaginous ring structure. The model describes the deposition of charged particles in the different generations of the tracheobronchial tree of the human lung. The upper airways are characterized by a certain wall structure called cartilaginous rings which modify the particle deposition when compared to an airway with a smooth wall. The problem is defined by solving Naver-Stokes equations in combination with a convective-diffusion equation and Gauss law for electrostatics. Three non- dimensional parameters describe the problem, the Peclet number Pe = 2ūa/D , the Reynolds number Re = ūa/v and an electrostatic parameter α=α2c0q2/(4ε0κT) . Here U is the mean velocity, a the pipe radius and D the diffusion coefficient due to Brownian motion given by D=κTCu/3πμd , where Cu is the Cunningham-factor Cu=1+λ/d(2.34+1.05exp(-0.39d/λ)) Here d is the particle diameter and λ the mean free path of the air molecules. Results are provided for generations G4-G16 of the human airways. The electrostatic parameter is varied to model different concentrations and charge numbers.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

Akerstedt, H. (2011) Deposition of charged nano-particles in the human airways including effects from cartilaginous rings. Natural Science, 3, 884-888. doi: 10.4236/ns.2011.310113.

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