%0 Journal Article
%T Deposition of charged nano-particles in the human  airways including effects from cartilaginous rings
%A Hans O. Akerstedt
%J Natural Science
%P 884-888
%@ 2150-4105
%D 2011
%I Scientific Research Publishing
%R 10.4236/ns.2011.310113
%X 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 <i>Pe = 2<span style=\"font-size:xx-small;\">¨±</span>a/D</i> , the Reynolds number <i>Re = <span style=\"font-size:xx-small;\">¨±</span>a/v </i> and an electrostatic parameter <i>¦Á</i>=<i>¦Á</i><sup>2</sup><i>c</i><sub>0</sub><i>q</i><sup>2</sup>/(4<i>¦Å</i><sub>0</sub><i>¦ÊT</i>)  . Here <i>U</i> is the mean velocity, a the pipe radius and <i>D</i> the diffusion coefficient due to Brownian motion given by <i>D</i>=<i>¦ÊTCu</i>/3<i>¦Ð¦Ìd</i> , where <i>Cu</i> is the Cunningham-factor <i>Cu</i>=1+<i>¦Ë/d</i>(2.34+1.05exp(-0.39<i>d/¦Ë</i>))  Here <i>d</i> is the particle diameter and <i>¦Ë</i> 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.
%K Charged Particles
%K Nanoparticles
%K Convection
%K Brownian motion
%K Deposition
%K Respiratory Airways
%K Cartilaginous Rings
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=8094