Unsteady-State Evaporation in an Infinite Tube

This Demonstration shows the unsteady-state evaporation of a liquid in bulk of vapor in an infinite tube, as governed by the following equation:

,

with

, .

Here is the diffusion coefficient, is the time, is the mole fraction of compound in the gaseous phase, is the nondimensional media molar velocity, and is the vertical position in the tube.

The boundary conditions are

at ,

at .

The problem is solved here using a shooting technique.