The partial differential equations governing the forced
convection motion of a drying fluid in a 2-D geometry
are the mass, momentum and energy conservation equations.
In the simplified case, thermophysical properties
are assumed to be constant. Considering the flow incompressible,
for a two-dimensional problem, the most general
form of the Navier–Stokes equations is summarized
below:
The mass conservation (i.e. continuity) equation is