Deposition by inertial impaction occurs when particles of sufficient momentum cannot follow the abrupt directional changes in the airways. The particles instead follow their original direction, causing them to impact the airway walls when the air ducts change direction. The probability that a particle of diameter d and density p will diverge from an airstream of velocity u is characterized by the Stokes number :
where h is the fluid viscosity and G is a constant that characterizes the geometry of the structure in which the particles are traveling. Therefore, deposition by impaction increases in proportion to (d^u). Inertial impaction is most significant for particles with large mass (determined by particle size and density) and/or velocity (determined by the respiratory flow velocity). Inertial impaction occurs mostly in the upper lung regions, since flowrates are high and changes in flow direction occur abruptly. Forced breathing increases particle velocity, thereby shifting particle deposition patterns towards the upper airways.
Was this article helpful?
Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...