Dry air is inhaled at a rate of 10 liter/min through a trachea with a diameter of 20 mm and a length of 125 mm. The inner surface of the trachea is at a normal body temperature of 37°C and may be assumed to be saturated with water.
(a) Assuming steady, fully developed flow in the trachea, estimate the mass transfer convection coefficient.
(b) Estimate the daily water loss (liter/day) associated with evaporation in the trachea.