A physical model of time-dependent flow in the human air passages

A physical model of the time-dependent, homogeneous, viscous and incompressible flow in the first twelve bronchial branches is described. The anatomical data given by Weibel (1963) are used. By means of these hypotheses we obtain the following equation: Palv(t) = K1V'B(t) + K2VB2'(T), where K1 and K2 are constants which depend on bronchial geometry and Palv(t) and VB(t) are the alveolar pressure and the mouth flow rate, respectively. Some results concerning laterobronchial pressure and velocities are given.